Please include the answers and how to solve

You buy a 20 -year bond with a coupon rate of 7.6% that has a yieid to maturity of 9.7%. (Assume a foce value of $1,000 and semiannual coupon payments.) Six months later, the yleid to maturity is 10.7%. What is your return over the 6 months? Note: Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places. Negative amount should be indicated by a minus sign