Mango Inc. is going to issue a $25-$year bond with a coupon rate of $7\mathrm{.}50\%($with $6$ coupon payments per year$)$ and a face value of $$1,000.$ Mango Inc. believes it can be rated A by Standard and Poor's. However, because of recent financial difficulties at the company, Standard and Poor's is warning that it may downgrade Mango Inc. Industries bonds to BBB$.$ Yields on A$-$rated, long$-$term bonds are currently $3\mathrm{.}00\%($quoted as an annual percentage rate $($APR$)),$ and yields on BBB$-$rated bonds are $7\mathrm{.}00\%($quoted as APR$).$ What is the $\%$ change in the price of the bond if it is downgraded?Instructions: Round the result to two decimal places and do not put the $"\%"$ symbol in the answer box. For example if you get a result of $-7\mathrm{.}5432\%$ then write $-7\mathrm{.}54$ in the answer box below.