Where:

P_k = Total payment, including interest, due on the k^th payment date following the prepayment date. n = Total number of remaining payment dates. I = The discount rate applied to each transaction will be ascertained by using data specified in the “Federal Reserve Statistical Release” which is published each Monday. (See appendix B to subpart E of this part.) The specific discount rate will be the discount rate(s) specified in the “Treasury Constant Maturities” section of this publication eight working days prior to the closing. In applying the discount rate, the 1-year Treasury rate will be used for all notes with a remaining term of less than 2 years; the 2-year Treasury rate for notes with maturities between 2 and 3 years; the 3-year Treasury rate for all notes with maturities between 3 and 5 years; the 5-year Treasury rate for all notes with maturities between 5 and 7 years; the 7-year Treasury rate for all notes with maturities between 7 and 10 years; the 10-year Treasury rate for all notes with maturities between 10 and 30 years; and the 30-year Treasury rate for all notes with maturities longer than 30 years.

D1_i = Number of days in the i^th payment period that are in a non-leap year (365 day year).

D2_i = Number of days in the i^th payment period that are in a leap year (366 day year).