Chris Anderson bought $10-$year, $11\mathrm{.}50$ percent coupon bonds issued by the U$.$S$.$ Treasury three years ago at $$912\mathrm{.}38.$ If he sells these $$1,000$ face value bonds, at the current price of $$840\mathrm{.}18,$ what is his realized yield on the bonds? Assume similar coupon$-$paying bonds make annual coupon payments. $($Round intermediate calculations to $5$ decimal places, e$.$g$.1\mathrm{.}25145$ and final answer to $2$ decimal places, e$.$g$.15\mathrm{.}25\%.)$

Realised rate of return $\%$