Included in the refining and wholesale marketing gross margins were pretax derivative losses of $899 million in 2007 and gains of $400 million in 2006.
For a more complete explanation of our strategies to manage market risk related to commodity prices, see Item 7A.
Quantitative and Qualitative Disclosures about Market Risk.
We averaged 1,010 mbpd of crude oil throughput in 2007 and 980 mbpd in 2006.
Our reported crude oil refining capacity increased to 1,016 mbpd in 2007 from 974 mbpd in 2006 due to overall efficiency gains in the operation of the refining units, reflecting the cumulative effect of regular maintenance, capital improvements and other process optimization efforts.
The following table includes certain key operating statistics for the RM&T segment for 2007 and 2006.
## Table 0 ##
(a) Sales revenue less cost of refinery inputs (including transportation), purchased products and manufacturing expenses, including depreciation.
IG segment income increased $116 million in 2007 from 2006.
During 2007, construction of the LNG production facility in Equatorial Guinea was completed ahead of schedule and on budget.
The increase in 2007 segment income over the previous year was largely due to the facility beginning operations in May 2007 and delivering 24 cargoes during the year.
Additionally, income from our equity method investment in AMPCO was higher in 2007 on increased methanol production due to plant downtime in 2006 and higher realized prices in 2007.
In 2006, a $17 million pretax loss was recognized as a result of the renegotiation of a technology agreement and income from our equity method investment in AMPCO was lower due to plant downtime during a planned turnaround and subsequent compressor repair.
Management’s Discussion and Analysis of Financial Condition, Cash Flows and Liquidity Cash Flows Net cash provided from operating activities totaled $6,782 million in 2008, compared to $6,521 million in 2007 and $5,488 million in 2006.
The $261 million increase in 2008 primarily reflects the impact of higher average realized prices.
The $1,033 million increase in 2007 primarily reflects working capital changes partially offset by lower net income.
Net cash used in investing activities totaled $5,435 million in 2008, compared with $8,102 million in 2007 and $2,955 million in 2006.
Significant investing activities include capital expenditures, acquisitions of businesses and asset disposals.
Capital expenditures by segment for continuing operations for each of the last three years are summarized in the following table.
## Table 1 ##
Capital expenditures for multiple years are impacted by the following projects.
In our E&P segment, development and completion of the Alvheim/Vilje project affected our capital expenditures in 2006, 2007 and to a lesser extent in 2008.
Similarly, our Angola exploration and development projects impacted all three years.
In our RM&T segment, the expansion of our Garyville, Louisiana refinery commenced with front-end engineering and design (“FEED”) in 2006 followed by construction in 2007 and 2008.
Also in RM&T, the expansion and upgrading
Supplementary Information on Oil and Gas Producing Activities (Unaudited)1082018 proved reserves decreased by 168 mmboe primarily due to the following:?
Revisions of previous estimates: Increased by 84 mmboe including an increase of 108 mmboe associated with the acceleration of higher economic wells in the U. S.  resource plays into the 5-year plan and an increase of 15 mmboe associated with wells to sales that were additions to the plan, partially offset by a decrease of 39 mmboe due to technical revisions across the business.  ?
Extensions, discoveries, and other additions: Increased by 102 mmboe primarily in the U. S.  resource plays due to an increase of 69 mmboe associated with the expansion of proved areas and an increase of 33 mmboe associated with wells to sales from unproved categories.  ?
Production: Decreased by 153 mmboe. ?
Sales of reserves in place: Decreased by 201 mmboe including 196 mmboe associated with the sale of our subsidiary in Libya, 4 mmboe associated with divestitures of certain conventional assets in New Mexico and Michigan, and 1 mmboe associated with the sale of the Sarsang block in Kurdistan.2017 proved reserves decreased by 647 mmboe primarily due to the following:?
Revisions of previous estimates: Increased by 49 mmboe primarily due to the acceleration of higher economic wells in the Bakken into the 5-year plan resulting in an increase of 44 mmboe, with the remainder being due to revisions across the business. ?
Extensions, discoveries, and other additions: Increased by 116 mmboe primarily due to an increase of 97 mmboe associated with the expansion of proved areas and wells to sales from unproved categories in Oklahoma. ?
Purchases of reserves in place: Increased by 28 mmboe from acquisitions of assets in the Northern Delaware Basin in New Mexico. ?
Production: Decreased by 145 mmboe. ?
Sales of reserves in place: Decreased by 695 mmboe including 685 mmboe associated with the sale of our Canadian business and 10 mmboe associated with divestitures of certain conventional assets in Oklahoma and Colorado.
See Item 8.
Financial Statements and Supplementary Data - Note 5 to the consolidated financial statements for information regarding these dispositions.2016 proved reserves decreased by 67 mmboe primarily due to the following:?
Revisions of previous estimates: Increased by 63 mmboe primarily due to an increase of 151 mmboe associated with the acceleration of higher economic wells in the U. S.  resource plays into the 5-year plan and a decrease of 64 mmboe due to U. S.  technical revisions.  ?
Extensions, discoveries, and other additions: Increased by 60 mmboe primarily associated with the expansion of proved areas and new wells to sales from unproven categories in Oklahoma.  ?
Purchases of reserves in place: Increased by 34 mmboe from acquisition of STACK assets in Oklahoma. ?
Production: Decreased by 144 mmboe. ?
Sales of reserves in place: Decreased by 84 mmboe associated with the divestitures of certain Wyoming and Gulf of Mexico assets.
Changes in Proved Undeveloped ReservesAs of December 31, 2018, 529 mmboe of proved undeveloped reserves were reported, a decrease of 17 mmboe from December 31, 2017.
The following table shows changes in proved undeveloped reserves for 2018:
## Table 2 ##
MARATHON OIL CORPORATIONNotes to Consolidated Financial Statements93Expected long-term return on plan assets – The expected long-term return on plan assets assumption for our U. S.  funded plan is determined based on an asset rate-of-return modeling tool developed by a third-party investment group which utilizes underlying assumptions based on actual returns by asset category and inflation and takes into account our U. S.  pension plan’s asset allocation.
To determine the expected long-term return on plan assets assumption for our international plans, we consider the current level of expected returns on risk-free investments (primarily government bonds), the historical levels of the risk premiums associated with the other applicable asset categories and the expectations for future returns of each asset class.
The expected return for each asset category is then weighted based on the actual asset allocation to develop the overall expected long-term return on plan assets assumption.
Assumed weighted average health care cost trend rates
## Table 3 ##
Employer provided subsidies for post-65 retiree health care coverage were frozen effective January 1, 2017 at January 1, 2016 established amount levels.
Company contributions are funded to a Health Reimbursement Account on the retiree’s behalf to subsidize the retiree’s cost of obtaining health care benefits through a private exchange (the “post-65 retiree health benefits”).
Therefore, a 1% change in health care cost trend rates would not have a material impact on either the service and interest cost components and the postretirement benefit obligations.
In the fourth quarter of 2018, we terminated the post-65 retiree health benefits effective as of December 31, 2020.
The post-65 retiree health benefits will no longer be provided after that date.
In addition, the pre-65 retiree medical coverage subsidy has been frozen as of January 1, 2019, and the ability for retirees to opt in and out of this coverage, as well as pre-65 retiree dental and vision coverage, has also been eliminated.
Retirees must enroll in connection with retirement for such coverage, or they lose eligibility.
These plan changes reduced our retiree medical benefit obligation by approximately $99 million.
Plan investment policies and strategies – The investment policies for our U. S.  and international pension plan assets reflect the funded status of the plans and expectations regarding our future ability to make further contributions.
Long-term investment goals are to: (1) manage the assets in accordance with applicable legal requirements; (2) produce investment returns which meet or exceed the rates of return achievable in the capital markets while maintaining the risk parameters set by the plan's investment committees and protecting the assets from any erosion of purchasing power; and (3) position the portfolios with a long-term risk/return orientation.
Investment performance and risk is measured and monitored on an ongoing basis through quarterly investment meetings and periodic asset and liability studies.
U. S.  plan – The plan’s current targeted asset allocation is comprised of 55% equity securities and 45% other fixed income securities.
Over time, as the plan’s funded ratio (as defined by the investment policy) improves, in order to reduce volatility in returns and to better match the plan’s liabilities, the allocation to equity securities will decrease while the amount allocated to fixed income securities will increase.
The plan's assets are managed by a third-party investment manager.
International plan – Our international plan's target asset allocation is comprised of 55% equity securities and 45% fixed income securities.
The plan assets are invested in ten separate portfolios, mainly pooled fund vehicles, managed by several professional investment managers whose performance is measured independently by a third-party asset servicing consulting firm.
Fair value measurements – Plan assets are measured at fair value.
The following provides a description of the valuation techniques employed for each major plan asset class at December 31, 2018 and 2017.
Cash and cash equivalents – Cash and cash equivalents are valued using a market approach and are considered Level 1.
Equity securities – Investments in common stock are valued using a market approach at the closing price reported in an active market and are therefore considered Level 1.
Private equity investments include interests in limited partnerships which are valued based on the sum of the estimated fair values of the investments held by each partnership, determined using a combination of market, income and cost approaches, plus working capital, adjusted for liabilities, currency translation and estimated performance incentives.
These private equity investments are considered Level 3.
Investments in pooled funds are valued using a market approach, these various funds consist of equity with underlying investments held in U. S.  and non-U.
S.  securities.
The pooled funds are benchmarked against a relative public index and are considered Level 2.
MARATHON OIL CORPORATION Notes to Consolidated Financial Statements Fixed income securities – Fixed income securities are valued using a market approach.
U. S.  treasury notes and exchange traded funds ("ETFs") are valued at the closing price reported in an active market and are considered Level 1.
Corporate bonds, private placements, and GNMA/FNMA/FHLMC pools are valued using calculated yield curves created by models that incorporate various market factors.
Primarily investments are held in U. S.  and non-U.
S.  corporate bonds in diverse industries and are considered Level 2.
Other fixed income investments include futures contracts, real estate investment trusts, credit default, zero coupon, interest rate swaps.
Investments in pooled funds are valued using a market approach, and primarily have investments held in U. S.  and non-U.
S.  publicly traded investment grade government and corporate bonds and are considered Level 2.
Other – Other investments are comprised of an unallocated annuity contract, two limited liability companies, and real estate.
All are considered Level 3, as significant inputs to determine fair value are unobservable.
Commingled funds – The investment in the commingled funds are valued using the net asset value of units held as a practical expedient.
The commingled funds consist of equity and fixed income portfolios with underlying investments held in U. S.  and non-U.
S.  securities.
The following tables present the fair values of our defined benefit pension plan's assets, by level within the fair value hierarchy, as of December 31, 2018 and 2017.
## Table 4 ##
December 31, 2017

<table><tr><td> RM&T Operating Statistics</td><td>2007</td><td>2006</td></tr><tr><td>Refining and wholesale marketing gross margin<i>(Dollars per gallon)</i><sup>(a)</sup></td><td>$0.1848</td><td>$0.2288</td></tr><tr><td>Refined products sales volumes<i>(Thousands of barrels per day)</i></td><td>1,410</td><td>1,425</td></tr></table>
<table><tr><td><i>(In millions)</i></td><td>2008</td><td>2007</td><td>2006</td></tr><tr><td>E&P</td><td></td><td></td><td></td></tr><tr><td>United States</td><td>$2,036</td><td>$1,354</td><td>$1,302</td></tr><tr><td>International</td><td>1,077</td><td>1,157</td><td>867</td></tr><tr><td>Total E&P</td><td>3,113</td><td>2,511</td><td>2,169</td></tr><tr><td>OSM</td><td>1,038</td><td>165</td><td>–</td></tr><tr><td>RM&T</td><td>2,954</td><td>1,640</td><td>916</td></tr><tr><td>IG</td><td>4</td><td>93</td><td>307</td></tr><tr><td>Corporate</td><td>37</td><td>57</td><td>41</td></tr><tr><td>Total</td><td>$7,146</td><td>$4,466</td><td>$3,433</td></tr></table>
<table><tr><td>Beginning of year</td><td>546</td></tr><tr><td>Revisions of previous estimates</td><td>47</td></tr><tr><td>Extensions, discoveries, and other additions</td><td>61</td></tr><tr><td>Dispositions</td><td>-19</td></tr><tr><td>Transfers to proved developed</td><td>-106</td></tr><tr><td>End of year</td><td>529</td></tr></table>
<table><tr><td></td><td>2018</td><td>2017</td><td>2016</td></tr><tr><td>Initial health care trend rate</td><td>N/A</td><td>8.00%</td><td>8.25%</td></tr><tr><td>Ultimate trend rate</td><td>N/A</td><td>4.70%</td><td>4.50%</td></tr><tr><td>Year ultimate trend rate is reached</td><td>N/A</td><td>2025</td><td>2025</td></tr></table>
<table><tr><td></td><td colspan="8">December 31, 2018</td></tr><tr><td>(In millions)</td><td colspan="2">Level 1</td><td colspan="2">Level 2</td><td colspan="2">Level 3</td><td colspan="2">Total</td></tr><tr><td></td><td>U.S.</td><td>Int’l</td><td>U.S.</td><td>Int’l</td><td>U.S.</td><td>Int’l</td><td>U.S.</td><td>Int’l</td></tr><tr><td>Cash and cash equivalents<sup>(a)</sup></td><td>$-1</td><td>$5</td><td>$—</td><td>$—</td><td>$—</td><td>$—</td><td>$-1</td><td>$5</td></tr><tr><td>Equity securities:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Common stock</td><td>75</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>75</td><td>—</td></tr><tr><td>Private equity</td><td>—</td><td>—</td><td>—</td><td>—</td><td>14</td><td>—</td><td>14</td><td>—</td></tr><tr><td>Pooled funds</td><td>—</td><td>—</td><td>—</td><td>191</td><td>—</td><td>—</td><td>—</td><td>191</td></tr><tr><td>Fixed income securities:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Corporate</td><td>—</td><td>—</td><td>4</td><td>—</td><td>—</td><td>—</td><td>4</td><td>—</td></tr><tr><td>Government</td><td>22</td><td>—</td><td>9</td><td>—</td><td>3</td><td>—</td><td>34</td><td>—</td></tr><tr><td>Pooled funds</td><td>—</td><td>—</td><td>—</td><td>398</td><td>—</td><td>—</td><td>—</td><td>398</td></tr><tr><td>Other</td><td>—</td><td>—</td><td>—</td><td>—</td><td>17</td><td>—</td><td>17</td><td>—</td></tr><tr><td>Total investments, at fair value</td><td>96</td><td>5</td><td>13</td><td>589</td><td>34</td><td>—</td><td>143</td><td>594</td></tr><tr><td>Commingled funds<sup>(b)</sup></td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>60</td><td>—</td></tr><tr><td>Total investments</td><td>$96</td><td>$5</td><td>$13</td><td>$589</td><td>$34</td><td>$—</td><td>$203</td><td>$594</td></tr></table>

Question: what percent of increases in extensions , discoveries , and other additions was associated with the expansion of proved areas and wells to sales from unproved categories in oklahoma?
Answer: 0.83621