Today is your son's twelfth birthday! Congrats! Time to start saving money for college, which will coincidentally start on your son's eighteenth birthday. You remembered that your local bank has recently started offering its customers a great program that allows you to save up for your child's future education when the child turns twelve. Under this program, you would need to make exactly six deposits, each in the amount of $13,500. The first deposit would need to be made today. And once your child turns eighteen and starts college, the bank would allow you to withdraw $27,000 right away, and repeat the money withdrawals from the same account (that continues earning interest) in the same amount once a year, with a total of four withdrawals to cover the college tuition. What annual interest rate does the bank offer on this college savings program? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 12.34) Return %