A major property developer is concerned about lack of sales due to local economic conditions. To ensure that his condos are occupied, he offers a lease-to-purchase program in which, if people sign a lease by the end of March, they will not have to start making payments until March of the following year. The purchase price of the condo is 177 000 $. Payments of $1205.73 will be required at the beginning of each month over a 25-year amortization period. If interest is 5.06% compounded semi-annually during the first year, what is the semi-annually compounded interest rate during the payment period?