What is the yield to call of a 30-year to maturity bond that pays a coupon rate of 8.62 percent per year, has a $1,000 par value, and is currently priced at $838? The bond can be called back in 4 years at a call price $1,071. Assume annual coupon payments. Round the answer to two decimal places in percentage form. (Write the percentage sign in the "units" box) You should use Excel or financial calculator.