The Gills have arranged a second mortgage loan with a face value of $21,500 at an interest rate of 6.5% compounded monthly. The face value is to be fully amortized by equal monthly payments over a five-year period. The Gills received only $20,000 of the face value, the difference being a bonus retained by the lender. What is the actual cost of borrowing, including the bonus, expressed as an effective interest rate?