Billy purchased a treasury bond with exactly five years until maturity, which pays coupon annually. The bond has a par value of $1,000, a 5% annual coupon rate, and a current yield to maturity (YTM) of 6%. After exactly three years, John sold the bond to another investor, with the yield to maturity of 4%. He was always able to re-invest all his coupon income at a return of 3%. All rates are annual. What is his geometric average annual return over the 3-year period?