Greshak Corp currently has bonds outstanding that trade for $848.82 in the market. Each bond has a $1,000 par value, and annual coupon rate of 6.25% (paid semiannually), and have 23 years remaining to maturity. In the market, this bond currently has a 7.75% nominal yield to maturity, but it can be called in 5 years at a price of $1,050. What is the bond's yield to call? Please show work and use at least 4 decimal places for the answer.