The past five monthly returns for Kohls are $4\mathrm{.}11$ percent, $3\mathrm{.}62$ percent, $-1\mathrm{.}68$ percent, $9\mathrm{.}25$ percent, and $-2\mathrm{.}56$ percent. Compute the standard deviation of Kohls' monthly returns. $($Do not round intermediate calculations and round your final answer to $2$ decimal places.$)$