Bill buys a 10-year 1000 par value bond with semi-annual coupons paid at an annual rate of 8%. The price assumes an annual nominal yield of 8%, compounded semiannually. As Bill receives each coupon payment, he immediately puts the money into an account earning interest at an semi-annual effective rate of 5%. At the end of 10 years, immediately after Bill receives the final coupon payment and the redemption value of the bond, Bill has earned an annual effective yield of X% on his investment in the bond. Find X.