A risk manager asks a junior risk analyst to assess the prepayment risk on a pool of fixed-rate mortgages. In order to calculate the conditional prepayment rate (CPR) for the pool, the analyst begins by estimating the monthly prepayments on one selected mortgage. At origination, the 30-year mortgage was a USD 1,750,000 loan making monthly mortgage payments at a fixed mortgage rate of 8% per year. Assuming the borrower made a total payment on the mortgage of USD 15,950.00 in one specific month, and the loan balance at the beginning of that month was USD 1,644,235.78, what is the correct estimate of the prepayment amount for that month?