You are going to invest $$300$ into an investment each month for the next $30$ years. In the end, you want to have a balance of $$400,000.$ To achieve this goal, what does the investment have to be earning $($i$.$e$.$ the rate$)?$

Please give your answer correctly to $2$ decimal places. Express your answer as a percentage $($i$.$e$.6\mathrm{.}45$ not $0\mathrm{.}06),$ with no need for the percentage $(\%)$ sign.