Fifteen years ago. Namson and Co. issued 25-year coupon bonds. The yield to maturity at the time of issuance was 10 percent and the bonds sold at 120% of par value. The bonds are currently selling at 85% of par value. What is the current yield to maturity for these bonds? (Assume that the coupon is paid annuallyl. (Round your answer to 2 decimal places and record as a percent but without a percent sign. For example, record 18.3893 4.81 % as 18.39)