When Fund M started on $1/1/21,$ it had $$257,225,000$ in assets under management $($AUM$).$ The annual holding period return was $4\mathrm{.}25\%$ in $2021,-10\mathrm{.}83\%$ in $2022,$ and $17\mathrm{.}33\%$ in $2023.$ Some investors redeemed shares, resulting in a net cash outflow of $$120,204,000$ on $12/31/21.$ There were also new investors buying the fund shares, resulting in a net cash inflow of $$27,885,000$ on $12/31/22.$The standard deviation of the fund return is $\_\_\_\_\_\_\_\_\%$ per year during the three$-$year period.