"Kylee saved $$30,000$ in in the stock market $21$ years ago, and has been saving an additional $$240$ each month since then. If her current account balance is $$920,000,$ what annual interest rate did she earn? $($Enter your answer as a whole number with two decimal places. For example, if your answer is $10\mathrm{.}3682\%,$ enter $10\mathrm{.}37$ as your answer$)"$