The past five monthly returns for Kohls are $3\mathrm{.}88$ percent, $4\mathrm{.}47$ percent, $-2\mathrm{.}02$ percent, $9\mathrm{.}42$ percent, and $-2\mathrm{.}90$ percent. Compute the standard deviation of Kohls' monthly returns. $($Do not round intermediate calculations and round your final answer to $2$ decimal places.$)$

Standard deviation