You buy a $20-$year bond with a coupon rate of $7\mathrm{.}8\%$ that has a yield to maturity of $9\mathrm{.}9\%.($Assume a face value of $$1,000$ and semiannual coupon payments.$)$ Six months later, the yield to maturity is $10\mathrm{.}9\%.$ What is your return over the $6$ months?

Note: Do not round intermediate calculations. Enter your answer as a percent rounded to $2$ decimal places. Negative amount should be indicated by a minus sign.

Rate of return

$\%$