Consider a two$-$state economy: recession and boom. The probability of having a boom is $40\%.$ Suppose an asset will earn $-13\%$ in the recession and $20\%$ in the boom. What is the standard deviation of the asset return in percentage $(\%)?$

Note: Write your answer in $\%$ terms with $2$ or more decimal places. For example, write $2\mathrm{.}54(\%)$ instead of $0\mathrm{.}0254.$