Atlantis Fisheries issues zero coupon bonds on the market at a price of $364 per bond. Each bond has a face value of $1,000 payable at maturity in 18 years. It is callable in 9 years at a call price of $490. Using semi-annual compounding, what is the yield to call for these bonds? (Round your answer to 2 decimal places. Omit the "%" sign in your response.)