April Wine bought $425$ shares of stock at $$5\mathrm{.}50$ per share. Four years later, she sold the stock for $$21$ per share.

What was her annual growth rate $($rate of return, ROR$)$ for her capital? Use Appendix B$.($Round $"$PV Factor" to $3$ decimal places. Do not round intermediate calculations. Round the final answer to $2$ decimal places.$)$

Annual growth rate of return