Suppose you invest $2,500 in a fund earning 11% simple interest. Further suppose that you have the option at any time of closing this account and opening an account earning compound interest at an annual effective interest rate of 9%. At what instant should you do so in order to maximize your accumulation at the end of five years? (Round your answer to two decimal places.) years How about if you wish to maximize the accumulation at the end of ten years? (Round your answer to two decimal places.) years