Percentages of Original Class Principal (or Class Notional) Balances and Weighted Average Lives Security Group 1 PSA Prepayment Assumption Rates Classes F, FA, FB, FT, OL, SA, SL, SM and SN Distribution Date 0% 100% 275% 400% 600% Initial Percent .................. 100 100 100 100 100 July 2008............................ 99 95 89 85 78 July 2009............................ 98 89 75 65 51 July 2010............................ 97 82 61 49 32 July 2011............................ 96 76 51 36 20 July 2012............................ 95 71 42 27 13 July 2013............................ 94 65 34 20 8 July 2014............................ 92 60 28 15 5 July 2015............................ 91 55 23 11 3 July 2016............................ 89 51 19 8 2 July 2017............................ 88 47 15 6 1 July 2018............................ 86 43 12 5 1 July 2019............................ 84 39 10 3 0 July 2020............................ 82 36 8 3 0 July 2021............................ 79 32 7 2 0 July 2022............................ 77 29 5 1 0 July 2023............................ 74 26 4 1 0 July 2024............................ 71 23 3 1 0 July 2025............................ 68 21 3 1 0 July 2026............................ 64 18 2 0 0 July 2027............................ 60 16 2 0 0 July 2028............................ 56 14 1 0 0 July 2029............................ 52 12 1 0 0 July 2030............................ 47 10 1 0 0 July 2031............................ 42 8 0 0 0 July 2032............................ 36 6 0 0 0 July 2033............................ 30 4 0 0 0 July 2034............................ 23 3 0 0 0 July 2035............................ 16 1 0 0 0 July 2036............................ 8 0 0 0 0 July 2037............................ 0 0 0 0 0 Weighted Average Life (years)  ..................   20.5 10.8 5.5 3.9 2.7 Security Group 2 PSA Prepayment Assumption Rates Classes AO, TM and TN Class BA Class BC Class BD Distribution Date 0% 100% 180% 250% 400% 0% 100% 180% 250% 400% 0% 100% 180% 250% 400% 0% 100% 180% 250% 400% Initial Percent .................. 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 July 2008............................ 100 100 100 79 30 100 100 84 60 9 100 100 100 100 100 100 100 100 100 100 July 2009............................ 100 100 100 50 0 100 100 61 6 0 100 100 100 100 0 100 100 100 100 0 July 2010............................ 100 100 100 29 0 100 100 42 0 0 100 100 100 7 0 100 100 100 100 0 July 2011............................ 100 100 100 15 0 100 100 27 0 0 100 100 100 0 0 100 100 100 58 0 July 2012............................ 100 100 100 6 0 100 100 17 0 0 100 100 100 0 0 100 100 100 28 0 July 2013............................ 100 100 100 2 0 100 100 10 0 0 100 100 100 0 0 100 100 100 9 0 July 2014............................ 100 100 100 1 0 100 100 5 0 0 100 100 100 0 0 100 100 100 1 0 July 2015............................ 100 100 100 0 0 100 100 3 0 0 100 100 100 0 0 100 100 100 0 0 July 2016............................ 100 100 100 0 0 100 100 0 0 0 100 100 97 0 0 100 100 100 0 0 July 2017............................ 100 100 95 0 0 100 100 0 0 0 100 100 84 0 0 100 100 100 0 0 July 2018............................ 100 100 89 0 0 100 100 0 0 0 100 100 68 0 0 100 100 100 0 0 July 2019............................ 100 100 83 0 0 100 100 0 0 0 100 100 51 0 0 100 100 100 0 0 July 2020............................ 100 100 76 0 0 100 100 0 0 0 100 100 33 0 0 100 100 100 0 0 July 2021............................ 100 100 68 0 0 100 100 0 0 0 100 100 15 0 0 100 100 100 0 0 July 2022............................ 100 100 61 0 0 100 100 0 0 0 100 100 0 0 0 100 100 98 0 0 July 2023............................ 100 100 55 0 0 100 88 0 0 0 100 100 0 0 0 100 100 87 0 0 July 2024............................ 100 100 48 0 0 100 71 0 0 0 100 100 0 0 0 100 100 77 0 0 July 2025............................ 100 100 42 0 0 100 54 0 0 0 100 100 0 0 0 100 100 67 0 0 July 2026............................ 100 100 36 0 0 100 37 0 0 0 100 100 0 0 0 100 100 58 0 0 July 2027............................ 100 100 31 0 0 100 20 0 0 0 100 100 0 0 0 100 100 49 0 0 July 2028............................ 100 100 26 0 0 100 4 0 0 0 100 100 0 0 0 100 100 41 0 0 July 2029............................ 100 90 21 0 0 100 0 0 0 0 100 71 0 0 0 100 100 34 0 0 July 2030............................ 100 76 17 0 0 100 0 0 0 0 100 33 0 0 0 100 100 27 0 0 July 2031............................ 100 61 13 0 0 100 0 0 0 0 100 0 0 0 0 100 98 21 0 0 July 2032............................ 100 48 10 0 0 100 0 0 0 0 100 0 0 0 0 100 76 16 0 0 July 2033............................ 100 35 7 0 0 100 0 0 0 0 100 0 0 0 0 100 55 11 0 0 July 2034............................ 100 22 4 0 0 100 0 0 0 0 100 0 0 0 0 100 35 7 0 0 July 2035............................ 100 10 2 0 0 38 0 0 0 0 100 0 0 0 0 100 17 3 0 0 July 2036............................ 72 0 0 0 0 0 0 0 0 0 23 0 0 0 0 100 0 0 0 0 July 2037............................ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Weighted Average Life (years)  ..................   29.3    24.9    17.4 2.3 0.7 27.8 18.2 3.0 1.2 0.6 28.9 22.6 12.0 2.6 1.3 29.6 26.3 20.5 4.5 1.7 S-18