Bonds issued by Glorious Vending Corporation have a coupon rate of $11\mathrm{.}99$ percent and a face value of $$1,000\mathrm{.}00,$ pay semi$-$annual coupons with one just paid and the next coupon due in $6$ months, and mature in $8$ years from today. Six months ago, the bonds were priced at $$828\mathrm{.}77.$ Today, the bond's yield$-$tomaturity $($YTM$)$ is $15\mathrm{.}17$ percent. What was the rate of return for the bonds over the past $6$ months $($from $6$ months ago until today$)?$

$10\mathrm{.}45\%($plus or minus $2bps)$

$17\mathrm{.}69\%($plus or minus $2bps)$

$18\mathrm{.}01\%($plus or minus $2bps)$

$27\mathrm{.}89\%($plus or minus $2bps)$

none of the answers are within $2bps$ of the correct answe