Uliana Company wants to issue new 21-year bonds for some much-needed expansion projects. The company currently has 9.1 percent coupon bonds on the market that sell for $1,131, make semiannual payments, have a par value of $1,000, and mature in 21 years. What coupon rate should the company set on its new bonds if it wants them to sell at par? (How is it done on Excel)