A stock had returns of $9\mathrm{.}1$ percent, $2$ percent, $-7\mathrm{.}9$ percent, $-3\mathrm{.}8$ percent, $13\mathrm{.}4$ percent, and $-5\mathrm{.}6$ percent over the past six years. What is the arithmetic average return for this time period? $\_\_\_\_\_\%$

Instruction: Enter your response as a percentage with two decimal places.

For example, if your answer is $0\mathrm{.}1213=12\mathrm{.}13\%,$ please only enter $"12\mathrm{.}13",$ please do not enter $"0\mathrm{.}1213"$ or $"12\mathrm{.}13\%",$ the system may not recognize the $\%$ sign. You may put negative signs if necessary,