A stock had returns of $7\%,2\%,25\%,-5\%,$ and $10\%$ over the past $5$ years.

What is the standard deviation for this stock?

$13\mathrm{.}7\%$

$11\mathrm{.}2\%$

$9\mathrm{.}0\%$

$9\mathrm{.}7\%$