Principal Financial Group, Inc.  Notes to Consolidated Financial Statements — (continued) 6.
Derivative Financial Instruments — (continued) We expect to reclassify net losses of $8.8 million from AOCI into net income in the next 12 months, which includes both net deferred losses on discontinued hedges and periodic settlements of active hedges.
Actual amounts may vary from this amount as a result of market conditions.
Net Investment in Foreign Operations Hedges From time to time, we take measures to hedge our net investments in our foreign subsidiaries from currency risks.
We did not use any currency forwards during 2009 or 2008 to hedge our net investment in foreign operations.
Derivatives Not Designated as Hedging Instruments Our use of futures, certain swaptions and swaps, options and currency forwards are effective from an economic standpoint, but they have not been designated as hedges for financial reporting purposes.
As such, periodic changes in the market value of these instruments, which includes mark-to-market gains and losses as well as periodic and final settlements, flow directly into net realized capital gains (losses).
The following tables show the effect of derivatives not designated as hedging instruments, including market value changes of embedded derivatives that have been bifurcated from the host contract, on the consolidated statements of operations for the years ended December 31, 2009, 2008 and 2007.
Gains (losses) are reported in net realized capital gains (losses) on the consolidated statements of operations.
## Table 0 ##
(1) Primarily includes the change in fair value of embedded derivatives.7.
Closed Block In connection with the 1998 MIHC formation, Principal Life formed a Closed Block to provide reasonable assurance to policyholders included therein that, after the formation of the MIHC, assets would be available to maintain dividends in aggregate in accordance with the 1997 policy dividend scales, if the experience underlying such scales continued.
Assets of Principal Life were allocated to the Closed Block in an amount that produces cash flows which, together with anticipated revenue from policies and contracts included in the Closed Block, were expected to be sufficient to support the Closed Block policies, including, but not limited to, provisions for payment of claims, certain expenses, charges and taxes, and to provide for continuation of policy and contract dividends in aggregate in accordance with the 1997 dividend scales, if the experience underlying such scales continues, and to allow for appropriate adjustments in such scales, if such experience changes.
Due to adjustable life policies being included in the Closed Block, the Closed Block is charged with amounts necessary to properly fund for certain adjustments, such as face amount and premium increases, that are made to these policies after the Closed Block inception date.
These amounts are referred to as Funding Adjustment Charges and are treated as capital transfers from the Closed Block.
Assets allocated to the Closed Block inure solely to the benefit of the holders of policies included in the Closed Block.
Closed Block assets and liabilities are carried on the same basis as other similar assets and liabilities.
Principal Life will continue to pay guaranteed benefits under all policies, including the policies within the Closed Block, in accordance with their terms.
If the assets allocated to the Closed Block, the investment cash flows from those assets and the revenues from the policies included in the Closed Block, including investment income thereon, prove to be insufficient to pay the benefits guaranteed under the policies included in the Closed Block, Principal Life will be required to make such payments from their general funds.
No additional policies were added to the Closed Block, nor was the Closed Block affected in any other way, as a result of the demutualization.
Our investment decisions and objectives are a function of the underlying risks and product profiles of each primary business operation.
In addition, we diversify our product portfolio offerings to include products that contain features that will protect us against fluctuations in interest rates.
Those features include adjustable crediting rates, policy surrender charges and market value adjustments on liquidations.
For further information on our management of interest rate risk, see Item 7A.
‘‘Quantitative and Qualitative Disclosures About Market Risk — Interest Rate Risk.
’’ Overall Composition of U. S.  Invested Assets As shown in the following table, the major categories of U. S.  invested assets are fixed maturity securities and commercial mortgage loans.
The remainder is invested in residential mortgage loans, real estate, equity securities and other assets.
In addition, policy loans are included in our invested assets.
The following discussion analyzes the composition of U. S.  invested assets, but excludes invested assets of the separate accounts.
## Table 1 ##
Fixed Maturity Securities Fixed maturity securities consist of publicly traded and privately placed bonds, mortgage-backed securities, redeemable preferred stock and certain nonredeemable preferred stock.
Included in the privately placed category as of December 31, 2009 and 2008, were $7.4 billion and $6.2 billion, respectively, of securities subject to certain holding periods and resale restrictions pursuant to Rule 144A of the Securities Act of 1933.
Fixed maturity securities include trading portfolios that support investment strategies that involve the active and frequent purchase and sale of fixed maturity securities.
We held $348.1 million of these trading securities as of December 31, 2009, and did not hold any of these securities as of December 31, 2008.
Fixed maturity securities were diversified by category of issuer as of December 31, 2009 and 2008, as shown in the following table:
## Table 2 ##
We believe that it is desirable to hold residential mortgage-backed pass-through securities due to their credit quality and liquidity as well as portfolio diversification characteristics.
Our portfolio is comprised of Government National Mortgage Association, Federal National Mortgage Association and Federal Home Loan Mortgage Corporation pass-through securities.
In addition, our residential collateralized mortgage obligation portfolio offers structural features that allow cash flows to be matched to our liabilities.
CMBS provide varying levels of credit protection, diversification and reduced event risk depending on the securities owned and composition of the loan pool.
CMBS are predominantly comprised of large pool securitizations that are diverse by property type, borrower and geographic dispersion.
The risks to any CMBS deal are determined by the credit
Non Duration-Managed.
We also have a block of participating general account pension business that passes most of the actual investment performance of the assets to the customer.
The investment strategy of this block is to maximize investment return to the customer on a ‘‘best efforts’’ basis, and there is little or no attempt to manage the duration of this portfolio since there is little or no interest rate risk.
The value of the assets in these portfolios was $5,745.5 million and $4,866.0 million as of December 31, 2009 and 2008, respectively.
Using the assumptions and data in effect as of December 31, 2009, we estimate that a 100 basis point immediate, parallel increase in interest rates increases the net fair value of our portfolio by approximately $71.1 million, compared with an estimated $34.0 million increase as of December 31, 2008.
The following table details the estimated changes by risk management strategy.
The table also gives the weighted-average duration of the asset portfolio for each category, and the net duration gap (i. e. , the weighted-average difference between the asset and liability durations).
## Table 3 ##
Our selection of a 100 basis point immediate, parallel increase or decrease in interest rates is a hypothetical rate scenario we use to demonstrate potential risk.
While a 100 basis point immediate, parallel increase does not represent our view of future market changes, it is a near term reasonably possible hypothetical change that illustrates the potential impact of such events.
While these fair value measurements provide a representation of interest rate sensitivity, they are based on our portfolio exposures at a point in time and may not be representative of future market results.
These exposures will change as a result of ongoing portfolio transactions in response to new business, management’s assessment of changing market conditions and available investment opportunities.
See Item 7.
‘‘Management’s Discussion and Analysis of Financial Condition and Results of Operation — Critical Accounting Policies and Estimates — Valuation of Invested Assets’’ for additional discussion of the impact interest rate increases would have on fixed maturities, available-for-sale.
Debt Issued and Outstanding.
The primary risk for our long-term borrowings is interest rate risk at the time of maturity or early redemption, when we may be required to refinance these obligations.
We continue to monitor the interest rate environment and to evaluate refinancing opportunities as maturity dates approach.
The aggregate fair value of long-term debt, excluding accrued interest, was $1,608.4 million and $1,096.1 million, as of December 31, 2009 and 2008, respectively.
As of December 31, 2009, a 100 basis point immediate, parallel decrease in interest rates would increase the fair value of debt by approximately $132.6 million, as compared to an estimated $59.4 million increase as of December 31, 2008.
As of December 31, 2009, a 100 basis point immediate, parallel increase in interest rates would decrease the fair value of debt by approximately $114.3 million, as compared to an estimated $52.9 million decrease as of December 31, 2008.
Debt is not recorded at fair value on the consolidated statements of financial position.
Our selection of a 100 basis point immediate, parallel increase or decrease in interest rates is a hypothetical rate scenario we use to demonstrate potential risk.
While a 100 basis point immediate, parallel increase or decrease does not represent our view of future market changes, it is a near term reasonably possible hypothetical change that illustrates the potential impact of such events.
While these fair value measurements provide a representation of interest rate sensitivity, they are based on our long-term debt obligations at a point in time and may not be representative of future obligations.
These exposures will change as a result of ongoing changes to our outstanding long-term debt obligations.
For additional information regarding our debt, see Item 8.
‘‘Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 10, Debt.
’’ Use of Derivatives to Manage Interest Rate Risk.
We use or have previously used various derivative financial instruments to manage our exposure to fluctuations in interest rates, including interest rate swaps, swaptions, futures, treasury lock agreements and options.
We use interest rate swaps and futures contracts to hedge changes in interest rates subsequent to the issuance of an insurance liability, such as a guaranteed investment contract, but prior to the purchase of a supporting asset, or during periods of holding assets in anticipation of near term liability sales.
We use interest rate swaps primarily to more closely match the interest rate characteristics of assets and liabilities.
They can be used to change the sensitivity to the interest rate of specific assets and liabilities as well as an entire portfolio.
Occasionally, we have sold a callable investment-type agreement and used written interest rate swaptions to transform the callable liability into a fixed term liability.
Derivatives in our portfolio with interest rate sensitivity were in a net liability position with a fair value of $130.7 million and $384.7 million as of December 31, 2009 and 2008, respectively.
The following table shows the interest
incentive compensation expense ($8.2 million) and related fringe benefit costs ($1.4 million), and higher warehousing costs due to customer requirements ($2.0 million).
Corporate overhead for the year ended December31,2006, increased $3.1 million, or 6.5%,fromtheyearendedDecember 31, 2005.
The increase was primarily attributable to higherincentivecompensation expense ($2.6million) and other increased costs which were not individually significant.
Otherexpense, net, decreased $2.1 million, or 20.1% for theyearended December31, 2006 comparedtothe year ended December 31, 2005.
The decrease was primarily due toa $3.1 million decrease inexpenses related to the disposals of property, plant and equipment aspart of planned disposals inconnection withcapital projects.
Partially offsetting the decreaseinfixed asset disposal expense washigher legal expenses ($0.5 million) and increasedlosses on disposals of storeroom items ($0.4 million).
Interest Expense, Net and IncomeTaxes Interest expense, net of interest income, increased by $3.1 million, or 11.1%, for the year ended December 31, 2006 compared tothe fullyear2005, primarily asa result of higher interestexpense onour variable rate debt due to higher interestrates.
PCA’s effective tax rate was 35.8% for the yearended December 31, 2006and 40.2% forthe yearended December 31,2005.
The lower taxrate in 2006 is primarily duetoalarger domestic manufacturer’s deduction and a reductionin the Texasstate tax rate.
Forbothyears2006and 2005, tax rateswerehigher than thefederalstatutory rate of35.0% due tostate income taxes.
Year EndedDecember 31, 2005 Compared to YearEnded December 31,2004The historical resultsofoperations of PCAfor theyears ended December 31, 2005 and 2004 are set forth below:

<table><tr><td> </td><td colspan="3">Amount of gain (loss) recognized in net income on derivatives for the year ended December 31,</td></tr><tr><td> Derivatives not designated as hedging instruments</td><td>2009</td><td>2008</td><td>2007</td></tr><tr><td> </td><td colspan="3">(in millions)</td></tr><tr><td>Interest rate contracts</td><td>$-58.7</td><td>$90.4</td><td>$-8.3</td></tr><tr><td>Foreign exchange contracts</td><td>87.9</td><td>-167.9</td><td>11.8</td></tr><tr><td>Equity contracts</td><td>-107.7</td><td>86.3</td><td>10.3</td></tr><tr><td>Credit contracts</td><td>61.7</td><td>-102.0</td><td>-67.2</td></tr><tr><td>Other contracts -1</td><td>21.6</td><td>-43.2</td><td>-22.2</td></tr><tr><td>Total</td><td>$4.8</td><td>$-136.4</td><td>$-75.6</td></tr></table>
<table><tr><td> </td><td colspan="2">December 31, 2009</td><td colspan="2"> December 31, 2008</td></tr><tr><td> </td><td> Carrying amount</td><td>% of total</td><td> Carrying amount</td><td> % of total</td></tr><tr><td> </td><td colspan="4"><i>($ in millions)</i> </td></tr><tr><td>Fixed maturity securities:</td><td></td><td></td><td></td><td></td></tr><tr><td>Public</td><td>$30,952.5</td><td>52%</td><td>$26,652.5</td><td>48%</td></tr><tr><td>Private</td><td>13,533.4</td><td>23</td><td>12,173.9</td><td>22</td></tr><tr><td>Equity securities</td><td>388.8</td><td>1</td><td>359.9</td><td>1</td></tr><tr><td>Mortgage loans:</td><td></td><td></td><td></td><td></td></tr><tr><td>Commercial</td><td>10,121.8</td><td>17</td><td>11,279.3</td><td>20</td></tr><tr><td>Residential</td><td>1,128.7</td><td>2</td><td>1,354.4</td><td>2</td></tr><tr><td>Real estate held for sale</td><td>23.8</td><td>—</td><td>135.4</td><td>—</td></tr><tr><td>Real estate held for investment</td><td>998.4</td><td>2</td><td>779.8</td><td>1</td></tr><tr><td>Policy loans</td><td>881.3</td><td>1</td><td>881.4</td><td>2</td></tr><tr><td>Other investments</td><td>1,480.2</td><td>2</td><td>2,162.4</td><td>4</td></tr><tr><td>Total invested assets</td><td>59,508.9</td><td>100%</td><td>55,779.0</td><td>100%</td></tr><tr><td>Cash and cash equivalents</td><td>2,192.3</td><td></td><td>2,537.0</td><td></td></tr><tr><td>Total invested assets and cash</td><td>$61,701.2</td><td></td><td>$58,316.0</td><td></td></tr></table>
<table><tr><td> </td><td colspan="2">December 31, 2009</td><td colspan="2"> December 31, 2008</td></tr><tr><td> </td><td> Carrying amount</td><td>% of total</td><td> Carrying amount</td><td> % of total</td></tr><tr><td> </td><td colspan="4"><i>($ in millions)</i> </td></tr><tr><td>U.S. Government and agencies</td><td>$781.9</td><td>2%</td><td>$595.2</td><td>1%</td></tr><tr><td>States and political subdivisions</td><td>2,218.2</td><td>5</td><td>2,176.7</td><td>6</td></tr><tr><td>Non-U.S. governments</td><td>462.4</td><td>1</td><td>478.5</td><td>1</td></tr><tr><td>Corporate — public</td><td>19,182.8</td><td>43</td><td>17,224.9</td><td>44</td></tr><tr><td>Corporate — private</td><td>11,604.7</td><td>26</td><td>10,365.4</td><td>27</td></tr><tr><td>Residential pass-through securities</td><td>3,367.7</td><td>7</td><td>2,187.9</td><td>6</td></tr><tr><td>Commercial mortgage-backed securities</td><td>3,602.9</td><td>8</td><td>3,607.1</td><td>9</td></tr><tr><td>Residential collateralized mortgage obligations</td><td>1,172.4</td><td>3</td><td>768.6</td><td>2</td></tr><tr><td>Asset-backed securities</td><td>2,092.9</td><td>5</td><td>1,422.1</td><td>4</td></tr><tr><td>Total fixed maturity securities</td><td>$44,485.9</td><td>100%</td><td>$38,826.4</td><td>100%</td></tr></table>
<table><tr><td> </td><td colspan="4"> December 31, 2009</td></tr><tr><td> Risk Management Strategy</td><td> Value of total assets <i>(in millions)</i> </td><td> Duration of assets</td><td>Net duration gap</td><td> Net fair value change <i>(in millions)</i> </td></tr><tr><td>Primary duration-managed</td><td>$28,377.1</td><td> 3.40</td><td>-0.12</td><td>$34.1</td></tr><tr><td>Duration-monitored</td><td>22,497.1</td><td> 4.13</td><td>-0.16</td><td>37.0</td></tr><tr><td>Non duration-managed</td><td>5,745.5</td><td> 3.83</td><td>N/A</td><td>N/A</td></tr><tr><td>Total</td><td>$56,619.7</td><td></td><td></td><td>$71.1</td></tr></table>

Question: What is the difference between the greatest mortgage loans in 2009 and 2008？ (in million)
Answer: -1157.5