Credit Ratings The credit ratings of the Ameren Companies affect our liquidity, our access to the capital markets and credit markets, our cost of borrowing under our credit facilities and collateral posting requirements under commodity contracts.
The following table presents the principal credit ratings of the Ameren Companies by Moody’s, S&P, and Fitch effective on the date of this report:
## Table 0 ##
(a) The BBB+ rating applies to issuances of securities secured by the mortgage associated with the former property of CILCO.
The BBB rating applies to issuances of securities secured by the mortgage associated with the former property of IP and CIPS.
The cost of borrowing under our credit facilities can also increase or decrease depending upon the credit ratings of the borrower.
A credit rating is not a recommendation to buy, sell, or hold securities.
It should be evaluated independently of any other rating.
Ratings are subject to revision or withdrawal at any time by the rating organization.
Collateral Postings Any adverse change in the Ameren Companies’ credit ratings may reduce access to capital and trigger additional collateral postings and prepayments.
Such changes may also increase the cost of borrowing and fuel, power, and natural gas supply, among other things, resulting in a negative impact on earnings.
Cash collateral postings and prepayments made with external parties, including postings related to exchange-traded contracts at December 31, 2011, were $145 million, $11 million, $102 million and $1 million at Ameren, Ameren Missouri, Ameren Illinois and Genco, respectively.
The amount of cash collateral external counterparties posted with Ameren was $6 million at December 31, 2011.
Sub-investment-grade issuer or senior unsecured debt ratings (lower than “BBB-” or “Baa3”) at December 31, 2011, could have resulted in Ameren, Ameren Missouri, Ameren Illinois or Genco being required to post additional collateral or other assurances for certain trade obligations amounting to $332 million, $86 million, $125 million, and $58 million, respectively.
Changes in commodity prices could trigger additional collateral postings and prepayments at current credit ratings.
If market prices were 15% higher than December 31, 2011, levels in the next 12 months and 20% higher thereafter through the end of the term of the commodity contracts, then Ameren, Ameren Missouri, Ameren Illinois and Genco could be required to post additional collateral or other assurances for certain trade obligations up to $119 million, $10 million, $- million, and $19 million, respectively.
If market prices were 15% lower than December 31, 2011, levels in the next 12 months and 20% lower thereafter through the end of the term of the commodity contracts, then Ameren, Ameren Missouri, Ameren Illinois and Genco could be required to post additional collateral or other assurances for certain trade obligations up to $227 million, $10 million, $69 million, and $81 million, respectively.
OUTLOOK Ameren seeks to earn competitive returns on its investments in its businesses.
Ameren Missouri and Ameren Illinois are seeking to improve their regulatory frameworks and cost recovery mechanisms.
At the same time, Ameren’s rate-regulated businesses are pursuing constructive regulatory outcomes within existing frameworks and are seeking to align their overall spending, both operating and capital, with economic conditions and cash flows provided by their regulators.
Consequently, Ameren’s rate-regulated businesses expect to narrow the historic gap between allowed and earned returns on equity.
Ameren’s Merchant Generation segment maintains a fleet of competitive coal-fired and natural gas generating assets.
Ameren’s merchant generation strategy is to position itself as a low-cost provider and to benefit from an expected future recovery of power prices.
Ameren intends to allocate its capital resources to those business opportunities, including electric and natural gas transmission, that offer the most attractive risk-adjusted return potential.
Below are some key trends, events, and uncertainties that are reasonably likely to affect the Ameren Companies’ financial condition, results of operations, or liquidity as well as their ability to achieve strategic and financial objectives for 2012 and beyond.
Rate-Regulated Operations ‰ Ameren’s strategy for earning competitive returns on its rate-regulated investments involves meeting customer energy needs in an efficient fashion, working to enhance regulatory frameworks, making timely and well-supported rate filings, and aligning overall spending with those rate case outcomes, economic conditions and return opportunities.
‰ The IEIMA, enacted late in 2011, provides for a performance-based formula ratemaking framework for electric delivery utilities in Illinois.
On January 3, 2012, Ameren Illinois elected to participate in this regulatory framework by making its initial performance-based formula rate filing with the ICC.
We believe that our
by a $1.4 billion increase in average loans and an increase in net FTPcredits, partially offset by lower loan yields.
Average deposits increased $1.4 billion.
The provision for credit losses of $28 million in 2014 increased $10 million from the prior year, primarily due to an increase in general Middle Market, partially offset by decreases in almost all other business lines.
Net credit-related charge-offs of $22 million in 2014 decreased $5 million compared to 2013, primarily reflecting decreases in most lines of business, partially offset by increases in Technology and Life Sciences and general Middle Market.
Noninterest income of $147 million in 2014 decreased $3 million from the prior year, primarily due to decreases of $3 million each in warrant income and securities trading income, partially offset by smaller increases in foreign exchange income, card fees and several other categories of noninterest income.
Noninterest expenses of $401 million in 2014 increased $5 million from the prior year, primarily reflecting a $7 million increase in corporate overhead expenses and small increases in several other noninterest expense categories, partially offset by a $6 million decrease in salaries and benefits expense and a $5 million decrease in losses related to foreclosed property.
See the Business Bank discussion for an explanation of the increase in corporate overhead expense.
The Texas market's net income decreased $17 million to $160 million in 2014, compared to $177 million in 2013.
Net interest income (FTE) of $542 million in 2014 increased $1 million from the prior year, primarily due to the benefit provided by a $965 million increase in average loans and lower deposit rates, partially offset by lower loan yields and a decrease in accretion of the purchase discount on the acquired loan portfolio.
Average deposits increased $517 million.
The provision for credit losses of $50 million in 2014 increased $15 million from the prior year, primarily reflecting increases in Energy, Commercial Real Estate and Technology and Life Sciences, partially offset by a decrease in Small Business.
Refer to the "Allowance for Credit Losses" and "Energy Lending" subheadings in the Risk Management section of this financial review for a discussion of the impact of the significant decline in oil and gas prices in the late third and fourth quarters of 2014 on the Corporation's portfolio of energy-related loans.
Net credit-related charge-offs of $9 million for 2014 decreased $11 million from the prior year, with decreases in almost all lines of business.
Noninterest income of $129 million in 2014 decreased $3 million from the prior year, primarily due to a decrease in syndication fees, a component of commercial lending fees.
Noninterest expenses of $369 million in 2014 increased $6 million from 2013, primarily due to an $8 million increase in corporate overhead expenses, partially offset by small decreases in several other categories of noninterest expenses.
See the Business Bank discussion, above, for an explanation of the increase in corporate overhead expense.
Net income in Other Markets of $221 million in 2014 increased $13 million compared to $208 million in 2013.
Net interest income (FTE) of $312 million in 2014 decreased $1 million from the prior year, primarily due to the impact of a decrease in average loans of $76 million and lower loan yields, partially offset by an increase in net FTPcredits.
Average deposits increased $476 million.
The provision for credit losses decreased $26 million in 2014, compared to the prior year, primarily reflecting decreases in general Middle Market, Environmental Services and Commercial Real Estate, partially offset by an increase in Mortgage Banker Finance.
Net credit-related recoveries were $14 million in 2014 compared to net charge-offs of $20 million in 2013, primarily reflecting decreases in general Middle Market, Commercial Real Estate and Environmental Services.
Noninterest income of $166 million in 2014 decreased $4 million from the prior year, primarily reflecting a $5 million decrease in income from the Corporation's third-party credit card provider, largely due to a change in the timing of the recognition of incentives from annually to quarterly in the third quarter 2013 and small decreases in several other noninterest income categories, partially offset by a $4 million increase in fiduciary income.
Noninterest expenses of $200 million in 2014 increased $3 million compared to the prior year, primarily due to a $3 million increase in corporate overhead expenses, a $3 million increase in efficiency-related occupancy expenses and small increases in several other noninterest expense categories, partially offset by a $7 million decrease in salaries and benefits expense.
See the Business Banking discussion for an explanation of the increase in corporate overhead expense.
The net loss for the Finance & Other category of $357 million in 2014 decreased $16 million compared to 2013, primarily reflecting a $19 million decrease in net loss in the Finance segment, largely due to the third quarter 2014 gain of $32 million on the early redemption of debt as previously discussed under the "Business Segments" subheading above.
The following table lists the Corporation's banking centers by geographic market segment.
## Table 1 ##
a total debt-to-capital ratio of less than 60%.
Net worth is defined as the sum of common stock, paid-in capital and retained earnings, less treasury stock plus any cumulative goodwill impairment charges.
The calculation also excludes accumulated other comprehensive income/loss and Nonrecourse Financial Liabilities of Special Purpose Entities.
The total debt-to-capital ratio is defined as total debt divided by the sum of total debt plus net worth.
The Company was in compliance with all its debt covenants at December 31, 2016 and was well below the thresholds stipulated under the covenants as defined in the credit agreements.
The Company will continue to rely upon debt and capital markets for the majority of any necessary long-term funding not provided by operating cash flows.
Funding decisions will be guided by our capital structure planning objectives.
The primary goals of the Company’s capital structure planning are to maximize financial flexibility and preserve liquidity while reducing interest expense.
The majority of International Paper’s debt is accessed through global public capital markets where we have a wide base of investors.
Maintaining an investment grade credit rating is an important element of International Paper’s financing strategy.
At December 31, 2016, the Company held long-term credit ratings of BBB (stable outlook) and Baa2 (stable outlook) by S&P and Moody’s, respectively.
Contractual obligations for future payments under existing debt and lease commitments and purchase obligations at December 31, 2016, were as follows:
## Table 2 ##
(a) Total debt includes scheduled principal payments only.
(b) Includes $2 billion relating to fiber supply agreements entered into at the time of the 2006 Transformation Plan forestland sales and in conjunction with the 2008 acquisition of Weyerhaeuser Company’s Containerboard, Packaging and Recycling business.
Also includes $1.1 billion relating to fiber supply agreements assumed in conjunction with the 2016 acquisition of Weyerhaeuser's pulp business.
(c) Not included in the above table due to the uncertainty as to the amount and timing of the payment are unrecognized tax benefits of approximately $77 million.
We consider the undistributed earnings of our foreign subsidiaries as of December 31, 2016, to be indefinitely reinvested and, accordingly, no U. S.  income taxes have been provided thereon.
As of December 31, 2016, the amount of cash associated with indefinitely reinvested foreign earnings was approximately $620 million.
We do not anticipate the need to repatriate funds to the United States to satisfy domestic liquidity needs arising in the ordinary course of business, including liquidity needs associated with our domestic debt service requirements.
Pension Obligations and Funding At December 31, 2016, the projected benefit obligation for the Company’s U. S.  defined benefit plans determined under U. S.  GAAP was approximately $3.4 billion higher than the fair value of plan assets.
Approximately $3.0 billion of this amount relates to plans that are subject to minimum funding requirements.
Under current IRS funding rules, the calculation of minimum funding requirements differs from the calculation of the present value of plan benefits (the projected benefit obligation) for accounting purposes.
In December 2008, the Worker, Retiree and Employer Recovery Act of 2008 (WERA) was passed by the U. S.  Congress which provided for pension funding relief and technical corrections.
Funding contributions depend on the funding method selected by the Company, and the timing of its implementation, as well as on actual demographic data and the targeted funding level.
The Company continually reassesses the amount and timing of any discretionary contributions and elected to make contributions totaling $750 million for both years ended December 31, 2016 and 2015.
At this time, we do not expect to have any required contributions to our plans in 2017, although the Company may elect to make future voluntary contributions.
The timing and amount of future contributions, which could be material, will depend on a number of factors, including the actual earnings and changes in values of plan assets and changes in interest rates.
International Paper announced a voluntary, limited-time opportunity for former employees who are participants in the Retirement Plan of International Paper Company (the Pension Plan) to request early payment of their entire Pension Plan benefit in the form of a single lump sum payment.
The amount of total payments under this program was approximately $1.2 billion, and were made from Plan trust assets on June 30, 2016.
Based on the level of payments made, settlement accounting rules applied and resulted in a plan remeasurement as of the June 30, 2016 payment date.
As a result of settlement accounting, the Company recognized a pro-rata portion of the unamortized net actuarial loss, after remeasurement, resulting in a $439 million non-cash charge to the Company's earnings in the second quarter of 2016.
Additional payments of $8 million and $9 million were made during the third and fourth quarters, respectively, due to mandatory cash payouts and a small lump sum payout, and the Pension Plan was subsequently remeasured at September 30, 2016 and December 31, 2016.
As a result of settlement accounting, the Company recognized non-cash settlement charges of $3 million in both the third and fourth quarters of 2016.
Proved Undeveloped Reserves.
Proved undeveloped oil and gas reserves are reserves that are expected to be recovered from new wells on undrilled acreage, or from existing wells where a relatively major expenditure is required for recompletion.
For complete definitions of proved natural gas, natural gas liquids and crude oil reserves, refer to Regulation S-X, Rule 4-10(a)(2), (3) and (4).
Proved Gas Reserves (Unaudited) The following reserve schedule was developed by our reserve engineers and sets forth the changes in estimated quantities of proved natural gas reserves:
## Table 3 ##
(1) Other International includes Argentina.
We have entered into an agreement to sell our interest in Argentina effective July 1, 2007.
We expect the sale, which is subject to regulatory and partner approvals, to close in 2008.
(2) Increases for Ecuador are due to better than expected performance.
(3) The increase in US proved reserves includes 57 Bcf in the Wattenberg field and 40 Bcf in the Mid-continent area, primarily due to infill drilling activities.
(4) Purchase of minerals in place is the result of the Patina Merger.
See Note 3—Acquisitions and Divestitures.
(5) Increases for Ecuador and North Sea are due to better than expected performance.
(6) The increase in US proved reserves includes 140 Bcf in the Wattenberg field, 77 Bcf in the Piceance basin and 55 Bcf in the Mid-continent area, primarily due to infill drilling activities.
(7) Purchase of minerals in place includes 128 Bcf acquired in the purchase of U. S.  Exploration.
See Note 3—Acquisitions and Divestitures.
(8) Sale of minerals in place is primarily due to sale of Gulf of Mexico shelf properties.
See Note 3—Acquisitions and Divestitures.
(9) The negative revisions within the US are primarily due to 103 Bcf of natural gas being reflected in the proved oil reserve table as NGLs, partially offset by positive revisions resulting from an increase in commodity price.
West Africa’s positive revisions are primarily due to additional production allowances related to LNG sales.
Positive revisions in Ecuador are related to better than expected well performance.
(10) The increase in US proved reserves includes 142 Bcf in the Wattenberg field, 83 Bcf in the Piceance basin and 19 Bcf in the Niobrara trend, primarily due to infill drilling activities.

Tables referenced above, in order (Table 0 first):
<table><tr><td></td><td> Moody’s</td><td> S&P</td><td> Fitch</td></tr><tr><td> Ameren:</td><td></td><td></td><td></td></tr><tr><td>Issuer/corporate credit rating</td><td>Baa3</td><td>BBB-</td><td>BBB</td></tr><tr><td>Senior unsecured debt</td><td>Baa3</td><td>BB+</td><td>BBB</td></tr><tr><td>Commercial paper</td><td>P-3</td><td>A-3</td><td>F2</td></tr><tr><td> Ameren Missouri:</td><td></td><td></td><td></td></tr><tr><td>Issuer/corporate credit rating</td><td>Baa2</td><td>BBB-</td><td>BBB+</td></tr><tr><td>Secured debt</td><td>A3</td><td>BBB+</td><td>A</td></tr><tr><td> Ameren Illinois:</td><td></td><td></td><td></td></tr><tr><td>Issuer/corporate credit rating</td><td>Baa3</td><td>BBB-</td><td>BBB-</td></tr><tr><td>Secured debt</td><td>Baa1</td><td>BBB/BBB+<sup>(a)</sup></td><td>BBB+</td></tr><tr><td>Senior unsecured debt</td><td>Baa3</td><td>BBB-</td><td>BBB</td></tr><tr><td> Genco:</td><td></td><td></td><td></td></tr><tr><td>Issuer/corporate credit rating</td><td>-</td><td>BB</td><td>BB-</td></tr><tr><td>Senior unsecured debt</td><td>Ba1</td><td>BB</td><td>BB-</td></tr></table>
<table><tr><td>December 31</td><td>2014</td><td>2013</td><td>2012</td></tr><tr><td>Michigan</td><td>214</td><td>216</td><td>218</td></tr><tr><td>Texas</td><td>135</td><td>140</td><td>142</td></tr><tr><td>California</td><td>104</td><td>105</td><td>104</td></tr><tr><td>Other Markets:</td><td></td><td></td><td></td></tr><tr><td>Arizona</td><td>18</td><td>18</td><td>18</td></tr><tr><td>Florida</td><td>9</td><td>10</td><td>11</td></tr><tr><td>Canada</td><td>1</td><td>1</td><td>1</td></tr><tr><td>Total Other Markets</td><td>28</td><td>29</td><td>30</td></tr><tr><td>Total</td><td>481</td><td>490</td><td>494</td></tr></table>
<table><tr><td>In millions</td><td>2017</td><td>2018</td><td>2019</td><td>2020</td><td>2021</td><td>Thereafter</td></tr><tr><td>Maturities of long-term debt (a)</td><td>$239</td><td>$690</td><td>$433</td><td>$179</td><td>$612</td><td>$9,161</td></tr><tr><td>Lease obligations</td><td>119</td><td>91</td><td>69</td><td>51</td><td>38</td><td>125</td></tr><tr><td>Purchase obligations (b)</td><td>3,165</td><td>635</td><td>525</td><td>495</td><td>460</td><td>2,332</td></tr><tr><td>Total (c)</td><td>$3,523</td><td>$1,416</td><td>$1,027</td><td>$725</td><td>$1,110</td><td>$11,618</td></tr></table>
<table><tr><td></td><td colspan="7">Natural Gas and Casinghead Gas (MMcf)</td></tr><tr><td></td><td>United States</td><td>West Africa</td><td>Israel</td><td>Ecuador</td><td>North Sea</td><td>Other Int'l -1</td><td>Total</td></tr><tr><td>Proved reserves as of:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>December 31, 2004</td><td>519,735</td><td>917,409</td><td>417,293</td><td>119,341</td><td>11,714</td><td>1,369</td><td>1,986,861</td></tr><tr><td>Revisions of previous estimates-2</td><td>18,644</td><td>7,732</td><td>481</td><td>32,800</td><td>3,200</td><td>-1,301</td><td>61,556</td></tr><tr><td>Extensions, discoveries and other additions-3</td><td>144,335</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>144,335</td></tr><tr><td>Purchase of minerals in place-4</td><td>1,083,959</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1,083,959</td></tr><tr><td>Sale of minerals in place</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Production</td><td>-125,543</td><td>-23,938</td><td>-24,228</td><td>-8,321</td><td>-3,394</td><td>-68</td><td>-185,492</td></tr><tr><td>December 31, 2005</td><td>1,641,130</td><td>901,203</td><td>393,546</td><td>143,820</td><td>11,520</td><td>-</td><td>3,091,219</td></tr><tr><td>Revisions of previous estimates-5</td><td>-82,371</td><td>57,543</td><td>260</td><td>32,927</td><td>10,485</td><td>278</td><td>19,122</td></tr><tr><td>Extensions, discoveries and other additions-6</td><td>314,140</td><td>-</td><td>-</td><td>-</td><td>-</td><td></td><td>314,140</td></tr><tr><td>Purchase of minerals in place-7</td><td>141,610</td><td>2,532</td><td>-</td><td>-</td><td>-</td><td>-</td><td>144,142</td></tr><tr><td>Sale of minerals in place-8</td><td>-110,486</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-110,486</td></tr><tr><td>Production</td><td>-164,830</td><td>-16,579</td><td>-33,906</td><td>-8,933</td><td>-2,967</td><td>-108</td><td>-227,323</td></tr><tr><td>December 31, 2006</td><td>1,739,193</td><td>944,699</td><td>359,900</td><td>167,814</td><td>19,038</td><td>170</td><td>3,230,814</td></tr><tr><td>Revisions of previous estimates-9</td><td>-67,003</td><td>44,256</td><td>-52</td><td>29,872</td><td>-1,062</td><td>-170</td><td>5,841</td></tr><tr><td>Extensions, discoveries and other additions-10</td><td>315,687</td><td>-</td><td>-</td><td>-</td><td>3,086</td><td>-</td><td>318,773</td></tr><tr><td>Purchase of minerals in place</td><td>2,957</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>2,957</td></tr><tr><td>Sale of minerals in place</td><td>-1</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-1</td></tr><tr><td>Production</td><td>-150,457</td><td>-48,349</td><td>-40,449</td><td>-9,385</td><td>-2,276</td><td>-</td><td>-250,916</td></tr><tr><td>December 31, 2007</td><td>1,840,376</td><td>940,606</td><td>319,399</td><td>188,301</td><td>18,786</td><td>-</td><td>3,307,468</td></tr><tr><td>Proved developed reserves as of:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>December 31, 2004</td><td>430,513</td><td>447,347</td><td>360,428</td><td>119,341</td><td>11,714</td><td>1,118</td><td>1,370,461</td></tr><tr><td>December 31, 2005</td><td>1,278,788</td><td>431,142</td><td>336,681</td><td>143,820</td><td>11,520</td><td>-</td><td>2,201,951</td></tr><tr><td>December 31, 2006</td><td>1,255,271</td><td>359,691</td><td>303,035</td><td>167,814</td><td>19,038</td><td>170</td><td>2,105,019</td></tr><tr><td>December 31, 2007</td><td>1,259,331</td><td>830,191</td><td>262,534</td><td>188,301</td><td>15,700</td><td>-</td><td>2,556,057</td></tr></table>

Question: Which reserves occupies the greatest proportion in total amount (in 2004)?
Answer: 447347.0