Calculate the standard deviation of a stock's return for the years $1926$ to $1930.$

Round to the nearest hundredth. Answer in percent.

Year $19261927192819291930$

Return $12\mathrm{.}62\%30\mathrm{.}38\%44\mathrm{.}73\%5\mathrm{.}07\%27\mathrm{.}56\%$