The rates of return on AK Corp, stock over the last five years were $19$ percent, $11$ percent, $-7$ percent, $6$ percent, and $9$ percent. Over the same period, the returns on SE Company's stock were $16$ percent, $20$ percent, $-3$ percent, $3$ percent, and $14$ percent.

Find the risk $($standard deviation$)$ of the stock AK$.$ Do not round intermediate calculations. Enter your standard deviation as a percent rounded to $2$ decimal places.