A 6.5 percent coupon bond with 25 years left to maturity can be called in four years. The call premium is one year of coupon payments. It is offered for sale at $1,066. What is the yield to call o the bond? (Assume that interest payments are paid annually and par value is $1,000.) 6.08 percent 6.21 percent 6.19 percent 6.31 percent