impairment the following table presents net unrealized losses on securities available for sale as of december 31: .
in 2011 what was the amount of tax related to the unrealized losses reclassifications totaled $ 303 million , or $ 189 million after-tax,
the net unrealized amounts presented above excluded the remaining net unrealized losses related to reclassifications of securities available for sale to securities held to maturity . these unrealized losses related to reclassifications totaled $ 303 million , or $ 189 million after-tax , and $ 523 million , or $ 317 million after-tax , as of december 31 , 2011 and 2010 , respectively , and were recorded in accumulated other comprehensive income , or oci . refer to note 12 to the consolidated financial statements included under item 8 . the decline in these remaining after-tax unrealized losses related to reclassifications from december 31 , 2010 to december 31 , 2011 resulted primarily from amortization . we conduct periodic reviews of individual securities to assess whether other-than-temporary impairment exists . to the extent that other-than-temporary impairment is identified , the impairment is broken into a credit component and a non-credit component . the credit component is recorded in our consolidated statement of income , and the non-credit component is recorded in oci to the extent that we do not intend to sell the security . our assessment of other-than-temporary impairment involves an evaluation , more fully described in note 3 , of economic and security-specific factors . such factors are based on estimates , derived by management , which contemplate current market conditions and security-specific performance . to the extent that market conditions are worse than management 2019s expectations , other-than-temporary impairment could increase , in particular , the credit component that would be recorded in our consolidated statement of income . given the exposure of our investment securities portfolio , particularly mortgage- and asset-backed securities , to residential mortgage and other consumer credit risks , the performance of the u.s . housing market is a significant driver of the portfolio 2019s credit performance . as such , our assessment of other-than-temporary impairment relies to a significant extent on our estimates of trends in national housing prices . generally , indices that measure trends in national housing prices are published in arrears . as of september 30 , 2011 , national housing prices , according to the case-shiller national home price index , had declined by approximately 31.3% ( 31.3 % ) peak-to-current . overall , management 2019s expectation , for purposes of its evaluation of other-than-temporary impairment as of december 31 , 2011 , was that housing prices would decline by approximately 35% ( 35 % ) peak-to-trough . the performance of certain mortgage products and vintages of securities continues to deteriorate . in addition , management continues to believe that housing prices will decline further as indicated above . the combination of these factors has led to an increase in management 2019s overall loss expectations . our investment portfolio continues to be sensitive to management 2019s estimates of future cumulative losses . ultimately , other-than- temporary impairment is based on specific cusip-level detailed analysis of the unique characteristics of each security . in addition , we perform sensitivity analysis across each significant product type within the non-agency u.s . residential mortgage-backed portfolio . we estimate , for example , that other-than-temporary impairment of the investment portfolio could increase by approximately $ 10 million to $ 50 million , if national housing prices were to decline by 37% ( 37 % ) to 39% ( 39 % ) peak-to-trough , compared to management 2019s expectation of 35% ( 35 % ) described above . this sensitivity estimate is based on a number of factors , including , but not limited to , the level of housing prices and the timing of defaults . to the extent that such factors differ substantially from management 2019s current expectations , resulting loss estimates may differ materially from those stated . excluding the securities for which other-than-temporary impairment was recorded in 2011 , management considers the aggregate decline in fair value of the remaining .