Mortgage-backed securities For U. S.  mortgage-backed securities (and in particular for Alt-A and other mortgage-backed securities that have significant unrealized losses as a percentage of amortized cost), credit impairment is assessed using a cash flow model that estimates the cash flows on the underlying mortgages, using the security-specific collateral and transaction structure.
The model estimates cash flows from the underlying mortgage loans and distributes those cash flows to various tranches of securities, considering the transaction structure and any subordination and credit enhancements that exist in that structure.
The cash flow model incorporates actual cash flows on the mortgage-backed securities through the current period and then projects the remaining cash flows using a number of assumptions, including default rates, prepayment rates, and recovery rates (on foreclosed properties).
Management develops specific assumptions using as much market data as possible and includes internal estimates as well as estimates published by rating agencies and other third-party sources.
Default rates are projected by considering current underlying mortgage loan performance, generally assuming the default of (1) 10% of current loans, (2) 25% of 30–59 day delinquent loans, (3) 75% of 60–90 day delinquent loans and (4) 100% of 91+ day delinquent loans.
These estimates are extrapolated along a default timing curve to estimate the total lifetime pool default rate.
Other assumptions used contemplate the actual collateral attributes, including geographic concentrations, rating agency loss projections, rating actions and current market prices.
The key base assumptions for mortgage-backed securities as of December 31, 2009 are in the table below:
## Table 0 ##
In addition, cash flow projections are developed using more stressful parameters, and management assesses the results of those stress tests (including the severity of any cash shortfall indicated and the likelihood of the stress scenarios actually occurring based on the underlying pool’s characteristics and performance) to assess whether management expects to recover the amortized cost basis of the security.
If cash flow projections indicate that the Company does not expect to recover its amortized cost basis, the Company recognizes the estimated credit loss in earnings.
State and municipal securities Citigroup’s AFS state and municipal bonds consist mainly of bonds that are financed through Tender Option Bond programs.
The process for identifying credit impairment for bonds in this program as well as for bonds that were previously financed in this program is largely based on third-party credit ratings.
Individual bond positions must meet minimum ratings requirements, which vary based on the sector of the bond issuer.
The average portfolio rating, ignoring any insurance, is Aa3/AA-.
Citigroup monitors the bond issuer and insurer ratings on a daily basis.
In the event of a downgrade of the bond below the Aa3/AA-, the subject bond is specifically reviewed for potential shortfall in contractual principal and interest.
Citigroup has not recorded any credit impairments on bonds held as part of the Tender Option Bond program or on bonds that were previously held as part of the Tender Option Bond program.
The remainder of Citigroup’s AFS state and municipal bonds, outside of the above, are specifically reviewed for credit impairment based on instrument-specific estimates of cash flows, probability of default and loss given default.
Recognition and Measurement of Other-Than-Temporary Impairment The following table presents the total other-than-temporary impairments recognized during the 12 months ended December 31, 2009:
## Table 1 ##
LOCAL CONSUMER LENDING Local Consumer Lending (LCL), which constituted approximately 65% of Citi Holdings by assets as of December 31, 2009, includes a portion of Citigroup’s North American mortgage business, retail partner cards, Western European cards and retail banking, CitiFinancial North America, Primerica, Student Loan Corporation and other local consumer finance businesses globally.
At December 31, 2009, LCL had $358 billion of assets ($317 billion in North America).
About one-half of the assets in LCL as of December 31, 2009 consisted of U. S.  mortgages in the company’s CitiMortgage and CitiFinancial operations.
The North American assets consist of residential mortgage loans, retail partner card loans, student loans, personal loans, auto loans, commercial real estate, and other consumer loans and assets.
## Table 2 ##
NM Not meaningful 2009 vs.  2008 Revenues, net of interest expense decreased 22% versus the prior year, mostly due to lower net interest revenue.
Net interest revenue was 23% lower than the prior year, primarily due to lower balances, de-risking of the portfolio, and spread compression.
Net interest revenue as a percentage of average loans decreased 63 basis points from the prior year, primarily due to the impact of higher delinquencies, interest write-offs, loan modification programs, higher FDIC charges and CARD Act implementation (in the latter part of 2009), partially offset by retail partner cards pricing actions.
LCL results will continue to be impacted by the CARD Act.
Citi currently estimates that the net impact on LCL revenues for 2010 could be a reduction of approximately $50 to $150 million.
See also “North America Regional Consumer Banking” and “Managing Global Risk—Credit Risk” for additional information on the impact of the CARD Act to Citi’s credit card businesses.
Average loans decreased 12%, with North America down 11% and international down 19%.
Non-interest revenue decreased $1.1 billion mostly driven by the impact of higher credit losses flowing through the securitization trusts.
Operating expenses declined 30% from the prior year, due to lower volumes and reductions from expense re-engineering actions, and the impact of goodwill write-offs of $3.0 billion in the fourth quarter of 2008, partially offset by higher other real estate owned and collection costs.
Provisions for loan losses and for benefits and claims increased 14% versus the prior year reflecting an increase in net credit losses of $6.1 billion, partially offset by lower reserve builds of $2.7 billion.
Higher net credit losses were primarily driven by higher losses of $3.6 billion in residential real estate lending, $1.0 billion in retail partner cards, and $0.7 billion in international.
Assets decreased $58 billion versus the prior year, primarily driven by lower originations, wind-down of specific businesses, asset sales, divestitures, write-offs and higher loan loss reserve balances.
Key divestitures in 2009 included the FI credit card business, Italy consumer finance, Diners Europe, Portugal cards, Norway consumer, and Diners Club North America.2008 vs.  2007 Revenues, net of interest expense decreased 9% versus the prior year, mostly due to lower Non-interest revenue.
Net interest revenue declined 1% versus the prior year.
Average loans increased 3%; however, revenues declined, driven by lower balances, de-risking of the portfolio, and spread compression.
Non-interest revenue decreased $2 billion, primarily due to the impact of securitization in retail partners cards and the mark-to-market on the mortgage servicing rights asset and related hedge in real estate lending.
Operating expenses increased 31%, driven by the impact of goodwill write-offs of $3.0 billion in the fourth quarter of 2008 and restructuring costs.
Excluding one-time expenses, expenses were slightly higher due to increased volumes.
CORPORATE/OTHER Corporate/Other includes global staff functions (includes finance, risk, human resources, legal and compliance) and other corporate expense, global operations and technology (O&T), residual Corporate Treasury and Corporate items.
At December 31, 2009, this segment had approximately $230 billion of assets, consisting primarily of the Company’s liquidity portfolio, including $110 billion of cash and cash equivalents.
## Table 3 ##
2009 vs.  2008 Revenues, net of interest expense declined, primarily due to the pretax loss on debt extinguishment related to the repayment of the $20 billion of TARP trust preferred securities and the pretax loss in connection with the exit from the loss-sharing agreement with the U. S.  government.
Revenues also declined, due to the absence of the 2008 sale of Citigroup Global Services Limited recorded in O&T.
This was partially offset by a pretax gain related to the exchange offers, revenues and higher intersegment eliminations.
Operating expenses increased, primarily due to intersegment eliminations and increases in compensation, partially offset by lower repositioning reserves.2008 vs.  2007 Revenues, net of interest expense increased primarily due to the gain in 2007 on the sale of certain corporate-owned assets and higher intersegment eliminations, partially offset by improved Treasury hedging activities.
Operating expenses declined, primarily due to lower restructuring charges in 2008 as well as reductions in incentive compensation and benefits expense.
## Table 4 ##
Loans Loans are an extension of credit to individuals, corporations, or government institutions.
Loans vary across regions and industries and primarily include credit cards, mortgages, other real estate lending, personal loans, auto loans, student loans, and corporate loans.
The majority of loans are carried at cost with a minimal amount recorded at fair value.
Consumer and corporate loans comprised 72% and 28%, respectively, of Citi’s total loans (net of unearned income and before the allowance for loan losses) as of December 31, 2009.
During 2009, consumer loans (net of allowance for loan losses) decreased by $64 billion, or 14%, primarily due to a: ?
$33 billion, or 12%, decrease in mortgage and real estate loans; and ?
$17 billion, or 19%, decrease in credit card loans, mostly in the U. S.  These decreases were driven by tightened lending standards and credit activity during the year.
During 2009, corporate loans decreased $46 billion, or 22%, primarily driven by a decrease of $21 billion, or 20%, in commercial and industrial loans.
During 2009, average consumer loans (net of unearned income) of $456billion yielded an average rate of 7.8%, compared to $513billion and 8.9% in the prior year.
Average corporate loans of $190 billion yielded an average rate of 6.3% in 2009, compared to $221 billion and 7.7% in the prior year.
For further information, see “Loans Outstanding” under “Managing Global Risk—Credit Risk” and Note17 to the Consolidated Financial Statements.
Trading Account Assets (Liabilities) Trading account assets include debt and marketable equity securities, derivatives in a receivable position, residual interests in securitizations, and physical commodities inventory.
In addition, certain assets that Citigroup has elected to carry at fair value, such as certain loans and purchase guarantees, are also included in Trading account assets.
Trading account liabilities include securities sold, not yet purchased (short positions) and derivatives in a net payable position as well as certain liabilities that Citigroup has elected to carry at fair value.
All Trading account assets and Trading account liabilities are reported at their fair value, except for physical commodities inventory which is carried at the lower of cost or market, with unrealized gains and losses recognized in current income.
During 2009, Trading account assets decreased by $35 billion, or 9%, due to a: ?
$56 billion, or 49%, decrease in revaluation gains primarily consisting of decreases in interest rate and foreign exchange contracts as well as a decrease in netting agreements; ?
$16 billion, or 30%, decrease in mortgage loan securities driven by decreased agency and subprime debt; ?
$20 billion, or 172%, increase in U. S.  Treasury and federal agency securities; ?
$15 billion, or 27%, increase in foreign government securities; and ?
$7 billion, or 9%, increase in corporate and other debt securities.

Tables referenced above, in order (Table 0 first):
<table><tr><td>Prepayment rate</td><td>December 31, 2009 3–8 CRR</td></tr><tr><td>Loss severity-1</td><td>45%–75%</td></tr><tr><td>Unemployment rate</td><td>10%</td></tr><tr><td>Peak-to-trough housing price decline</td><td>32.3%</td></tr></table>
<table><tr><td>Other-Than-Temporary Impairments (OTTI) on Investments</td><td colspan="3">Year ended December 31, 2009</td></tr><tr><td>In millions of dollars</td><td>AFS</td><td>HTM</td><td>Total</td></tr><tr><td>Impairment losses related to securities that the Company does not intend to sell nor will</td><td></td><td></td><td></td></tr><tr><td>likely be required to sell</td><td></td><td></td><td></td></tr><tr><td>Total OTTI losses recognized during the year ended December 31, 2009</td><td>$468</td><td>$6,600</td><td>$7,068</td></tr><tr><td>Less: portion of OTTI loss recognized in AOCI (before taxes)</td><td>60</td><td>4,296</td><td>4,356</td></tr><tr><td>Net impairment losses recognized in earnings for securities that the Company does not intend</td><td></td><td></td><td></td></tr><tr><td>to sell nor will likely be required to sell</td><td>$408</td><td>$2,304</td><td>$2,712</td></tr><tr><td>OTTI losses recognized in earnings for securities that the Company intends to sell or more-</td><td></td><td></td><td></td></tr><tr><td>likely-than-not will be required to sell before recovery</td><td>194</td><td>—</td><td>194</td></tr><tr><td>Total impairment losses recognized in earnings</td><td>$602</td><td>$2,304</td><td>$2,906</td></tr></table>
<table><tr><td>In millions of dollars</td><td>2009</td><td>2008</td><td>2007</td><td>% Change 2009 vs. 2008</td><td>% Change 2008 vs. 2007</td></tr><tr><td>Net interest revenue</td><td>$13,709</td><td>$17,903</td><td>$18,166</td><td>-23%</td><td>-1%</td></tr><tr><td>Non-interest revenue</td><td>5,473</td><td>6,550</td><td>8,584</td><td>-16</td><td>-24</td></tr><tr><td>Total revenues, net of interest expense</td><td>$19,182</td><td>$24,453</td><td>$26,750</td><td>-22%</td><td>-9%</td></tr><tr><td>Total operating expenses</td><td>$10,431</td><td>$14,973</td><td>$11,457</td><td>-30%</td><td>31%</td></tr><tr><td>Net credit losses</td><td>$19,237</td><td>$13,151</td><td>$6,794</td><td>46%</td><td>94%</td></tr><tr><td>Credit reserve build/(release)</td><td>5,904</td><td>8,592</td><td>5,454</td><td>-31</td><td>58</td></tr><tr><td>Provision for benefits and claims</td><td>1,055</td><td>1,191</td><td>765</td><td>-11</td><td>56</td></tr><tr><td>Provision for unfunded lending commitments</td><td>3</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Provisions for loan losses and for benefits and claims</td><td>$26,199</td><td>$22,934</td><td>$13,013</td><td>14%</td><td>76%</td></tr><tr><td>Income (loss) from continuing operations before taxes</td><td>$-17,448</td><td>$-13,454</td><td>$2,280</td><td>-30%</td><td>NM</td></tr><tr><td>Income taxes (benefits)</td><td>-7,405</td><td>-5,200</td><td>568</td><td>-42</td><td>NM</td></tr><tr><td>Income (loss) from continuing operations</td><td>$-10,043</td><td>$-8,254</td><td>$1,712</td><td>-22%</td><td>NM</td></tr><tr><td>Net income attributable to noncontrolling interests</td><td>32</td><td>12</td><td>34</td><td>NM</td><td>-65%</td></tr><tr><td>Net income (loss)</td><td>$-10,075</td><td>$-8,266</td><td>$1,678</td><td>-22%</td><td>NM</td></tr><tr><td>Average assets(in billions of dollars)</td><td>$390</td><td>$461</td><td>$496</td><td>-15</td><td>-7%</td></tr><tr><td>Net credit losses as a percentage of average loans</td><td>5.91%</td><td>3.56%</td><td>1.90%</td><td></td><td></td></tr></table>
<table><tr><td>In millions of dollars</td><td>2009</td><td>2008</td><td>2007</td></tr><tr><td>Net interest revenue</td><td>$-1,663</td><td>$-2,680</td><td>$-2,008</td></tr><tr><td>Non-interest revenue</td><td>-8,893</td><td>422</td><td>-302</td></tr><tr><td>Total revenues, net of interest expense</td><td>$-10,556</td><td>$-2,258</td><td>$-2,310</td></tr><tr><td>Total operating expenses</td><td>$1,420</td><td>$510</td><td>$1,813</td></tr><tr><td>Provisions for loan losses and for benefits and claims</td><td>-1</td><td>1</td><td>-3</td></tr><tr><td>(Loss) from continuing operations before taxes</td><td>$-11,975</td><td>$-2,769</td><td>$-4,120</td></tr><tr><td>Income taxes (benefits)</td><td>-4,369</td><td>-587</td><td>-1,446</td></tr><tr><td>(Loss) from continuing operations</td><td>$-7,606</td><td>$-2,182</td><td>$-2,674</td></tr><tr><td>Income (loss) from discontinued operations, net of taxes</td><td>-445</td><td>4,002</td><td>708</td></tr><tr><td>Net income (loss) before attribution of noncontrolling interests</td><td>$-8,051</td><td>$1,820</td><td>$-1,966</td></tr><tr><td>Net income attributable to noncontrolling interests</td><td>—</td><td>—</td><td>2</td></tr><tr><td>Net income (loss)</td><td>$-8,051</td><td>$1,820</td><td>$-1,968</td></tr></table>
<table><tr><td></td><td colspan="2">December 31,</td><td rowspan="2">Increase% (decrease)</td><td></td></tr><tr><td>In billions of dollars</td><td>2009</td><td>2008</td><td>Change</td></tr><tr><td>Assets</td><td></td><td></td><td></td><td></td></tr><tr><td>Loans, net of unearned income and allowance for loan losses</td><td>$555</td><td>$665</td><td>$-110</td><td>-17%</td></tr><tr><td>Trading account assets</td><td>343</td><td>378</td><td>-35</td><td>-9</td></tr><tr><td>Federal funds sold and securities borrowed or purchased under agreements to resell</td><td>222</td><td>184</td><td>38</td><td>21</td></tr><tr><td>Investments</td><td>306</td><td>256</td><td>50</td><td>20</td></tr><tr><td>Other assets</td><td>431</td><td>455</td><td>-24</td><td>-5</td></tr><tr><td>Total assets</td><td>$1,857</td><td>$1,938</td><td>$-81</td><td>-4%</td></tr><tr><td>Liabilities</td><td></td><td></td><td></td><td></td></tr><tr><td>Deposits</td><td>$836</td><td>$774</td><td>$62</td><td>8%</td></tr><tr><td>Federal funds purchased and securities loaned or sold under agreements to repurchase</td><td>154</td><td>205</td><td>-51</td><td>-25</td></tr><tr><td>Short-term borrowings and long-term debt</td><td>433</td><td>486</td><td>-53</td><td>-11</td></tr><tr><td>Trading account liabilities</td><td>138</td><td>166</td><td>-28</td><td>-17</td></tr><tr><td>Other liabilities</td><td>141</td><td>163</td><td>-22</td><td>-13</td></tr><tr><td>Total liabilities</td><td>$1,702</td><td>$1,794</td><td>$-92</td><td>-5%</td></tr><tr><td>Stockholders’ equity</td><td>$155</td><td>$144</td><td>$11</td><td>8%</td></tr><tr><td>Total liabilities and stockholders’ equity</td><td>$1,857</td><td>$1,938</td><td>$-81</td><td>-4%</td></tr></table>

Question: what was the percentage change in total operating expenses between 2007 and 2008?
Answer: -0.7187
Reasoning program: subtract(510,1813), divide(#0,1813)