Security Group 2 PSA Prepayment Assumption Rates Distribution Date Class LJ 0% 125% 250% 375% 500% Class NI 0% 125% 250% 375% 500% Classes PA, PC, PD, PE, PG, PH, PI, PK, PL and PM 0% 125% 250% 375% 500% Class TI 0% 125% 250% 375% 500% Initial Percent ..................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2008................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2009................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2010................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2011................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2012................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2013................    100 100 100 100 98 100 100 100 100 93 100 100 100 100 90 100 100 100 100 91 December 2014................    100 100 100 100 87 100 100 100 100 56 100 100 100 100 36 100 100 100 100 43 December 2015................    100 100 100 98 75 100 100 100 93 29 100 100 100 89 0 100 100 100 90 10 December 2016................    100 99 99 89 51 100 98 98 63 20 100 97 97 46 0 100 97 97 52 7 December 2017................    100 97 97 82 35 100 90 90 39 14 100 85 85 11 0 100 87 87 20 4 December 2018................    100 90 90 67 24 100 64 64 26 9 100 48 48 0 0 100 53 53 9 3 December 2019................    100 83 83 50 16 100 44 44 20 6 100 18 18 0 0 100 26 26 6 2 December 2020................    100 75 75 38 11 100 29 29 15 4 100 0 0 0 0 100 10 10 5 1 December 2021................    100 59 59 28 7 100 23 23 11 3 100 0 0 0 0 100 8 8 4 1 December 2022................    100 47 47 21 5 100 18 18 8 2 100 0 0 0 0 100 6 6 3 1 December 2023................    100 37 37 16 3 100 14 14 6 1 100 0 0 0 0 100 5 5 2 0 December 2024................    100 29 29 11 2 100 11 11 4 1 100 0 0 0 0 100 4 4 1 0 December 2025................    100 22 22 8 1 100 9 9 3 1 100 0 0 0 0 100 3 3 1 0 December 2026................    100 17 17 6 1 100 7 7 2 0 100 0 0 0 0 100 2 2 1 0 December 2027................    100 13 13 4 1 98 5 5 2 0 98 0 0 0 0 98 2 2 1 0 December 2028................ 97 10 10 3 0 90 4 4 1 0 86 0 0 0 0 87 1 1 0 0 December 2029................ 86 7 7 2 0 52 3 3 1 0 30 0 0 0 0 37 1 1 0 0 December 2030................ 55 5 5 2 0 21 2 2 1 0 0 0 0 0 0 7 1 1 0 0 December 2031................ 4 4 4 1 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 December 2032................ 3 3 3 1 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 December 2033................ 2 2 2 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 December 2034................ 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 December 2035................ 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 December 2036................ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 December 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)  ..................   23.0    15.5    15.5    12.8 9.7 22.2 12.8 12.8 10.5 7.9 21.6 11.0 11.0 9.0 6.8 21.8 11.6 11.6 9.4 7.2 PSA Prepayment Assumption Rates Distribution Date Class UI 0% 125% 250% 375% 500% Class VI 0% 125% 250% 375% 500% Class WI 0% 125% 250% 375% 500% Class XI 0% 125% 250% 375% 500% Initial Percent ..................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2008................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2009................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2010................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2011................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2012................    100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 December 2013................    100 100 100 100 95 100 100 100 100 95 100 100 100 100 95 100 100 100 100 94 December 2014................    100 100 100 100 67 100 100 100 100 69 100 100 100 100 67 100 100 100 100 62 December 2015................    100 100 100 94 45 100 100 100 95 48 100 100 100 94 45 100 100 100 94 37 December 2016................    100 98 98 72 31 100 99 99 74 33 100 98 98 72 31 100 98 98 68 26 December 2017................    100 92 92 53 21 100 93 93 57 23 100 92 92 54 21 100 91 91 46 18 December 2018................    100 73 73 40 14 100 75 75 43 15 100 73 73 40 14 100 69 69 33 12 December 2019................    100 57 57 30 10 100 60 60 32 10 100 57 57 30 10 100 51 51 25 8 December 2020................    100 45 45 22 7 100 48 48 24 7 100 45 45 23 7 100 37 37 19 5 December 2021................    100 35 35 17 4 100 38 38 18 5 100 36 36 17 4 100 30 30 14 4 December 2022................    100 28 28 13 3 100 30 30 14 3 100 28 28 13 3 100 23 23 10 2 December 2023................    100 22 22 9 2 100 24 24 10 2 100 22 22 9 2 100 18 18 8 2 December 2024................    100 17 17 7 1 100 18 18 7 1 100 17 17 7 1 100 14 14 6 1 December 2025................    100 13 13 5 1 100 14 14 5 1 100 13 13 5 1 100 11 11 4 1 December 2026................    100 10 10 4 1 100 11 11 4 1 100 10 10 4 1 100 8 8 3 0 December 2027................ 99 8 8 3 0 99 8 8 3 0 99 8 8 3 0 99 6 6 2 0 December 2028................ 93 6 6 2 0 93 6 6 2 0 93 6 6 2 0 91 5 5 2 0 December 2029................ 63 4 4 1 0 66 5 5 1 0 64 4 4 1 0 58 4 4 1 0 December 2030................ 33 3 3 1 0 35 3 3 1 0 33 3 3 1 0 27 3 3 1 0 December 2031................ 2 2 2 1 0 2 2 2 1 0 2 2 2 1 0 2 2 2 1 0 December 2032................ 2 2 2 0 0 2 2 2 0 0 2 2 2 0 0 1 1 1 0 0 December 2033................ 1 1 1 0 0 1 1 1 0 0 1 1 1 0 0 1 1 1 0 0 December 2034................ 1 1 1 0 0 1 1 1 0 0 1 1 1 0 0 1 1 1 0 0 December 2035................ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 December 2036................ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 December 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)  ..................   22.5    13.7    13.7    11.3 8.5 22.5 13.9 13.9 11.4 8.7 22.5 13.7 13.7 11.3 8.6 22.3 13.2 13.2 10.9 8.2 S-28