A nine$-$year bond has a yield of $10\%$ and a duration of $7\mathrm{.}090$ years. If the bond's yield increases by $50$ basis points $($i$.$e$.,0\mathrm{.}5\%),$ what is the proportional change in the bond's price? Enter your answer as a decimal $($e$.$g$.,0\mathrm{.}01$ instead of $1\%),$ rounded to four decimal places, and don't forget the sign of the change.