Security Group 13
PSA Prepayment Assumption Rates
Class IV
Distribution Date
0%
75%
150%
250%
400%
Initial Percent .................. 100
100
100
100
100
May 2005 ..........................
94
80
65
59
58
May 2006 ..........................
88
60
33
21
19
May 2007 ..........................
82
41
20
16
13
May 2008 ..........................
75
22
16
12
9
May 2009 ..........................
68
19
13
8
6
May 2010 ..........................
60
17
10
5
4
May 2011 ..........................
51
14
7
4
3
May 2012 ..........................
42
12
5
3
2
May 2013 ..........................
33
9
3
2
1
May 2014 ..........................
23
7
1
1
1
May 2015 ..........................
17
5
1
1
0
May 2016 ..........................
15
4
0
0
0
May 2017 ..........................
13
2
0
0
0
May 2018 ..........................
10
1
0
0
0
May 2019 ..........................
9
0
0
0
0
May 2020 ..........................
7
0
0
0
0
May 2021 ..........................
5
0
0
0
0
May 2022 ..........................
3
0
0
0
0
May 2023 ..........................
1
0
0
0
0
May 2024 ..........................
0
0
0
0
0
May 2025 ..........................
0
0
0
0
0
May 2026 ..........................
0
0
0
0
0
May 2027 ..........................
0
0
0
0
0
May 2028 ..........................
0
0
0
0
0
May 2029 ..........................
0
0
0
0
0
May 2030 ..........................
0
0
0
0
0
May 2031 ..........................
0
0
0
0
0
May 2032 ..........................
0
0
0
0
0
May 2033 ..........................
0
0
0
0
0
May 2034 ..........................
0
0
0
0
0
Weighted Average
Life (years) ..................
7.5
3.5
2.2
1.8
1.7
Yield Considerations
An investor seeking to maximize yield should make a decision whether to invest in any
Class based on the anticipated yield of that Class resulting from its purchase price, the
investor's own projection of Mortgage Loan prepayment rates under a variety of scenarios, in the
case of the Group 3, 4, 7, 8, 9, 10, 11, 12 and 13 Securities, the investor's own projection of
payment rates on the Underlying Certificates under a variety of scenarios, and, in the case of a
Floating Rate or an Inverse Floating Rate Class, the investor's own projection of levels of LIBOR
under a variety of scenarios. No representation is made regarding Mortgage Loan prepay-
ment rates, Underlying Certificate payment rates, LIBOR levels or the yield of any
Class.
Prepayments: Effect on Yields
The yields to investors will be sensitive in varying degrees to the rate of prepayments on
the related Mortgage Loans.
• In the case of Regular Securities or MX Securities purchased at a premium (especially
Interest Only Classes), faster than anticipated rates of principal payments could result in
actual yields to investors that are lower than the anticipated yields.
• Investors in the Interest Only Classes should also consider the risk that rapid rates of
principal payments could result in the failure of investors to recover fully their
investments.
• In the case of Regular Securities or MX Securities purchased at a discount (especially
Principal Only Classes), slower than anticipated rates of principal payments could result
in actual yields to investors that are lower than the anticipated yields.
S-34