Your firm receives an offer from the supplier who provides computer chips used to manufacture cell phones. Due to poor planning, the supplier has an excess amount of chips and is willing to sell $609,268 worth of chips for only $432,650. You already have 5 years' supply on hand. It would cost you $6,218 today to store the chips until your firm needs them in 5 years. What implied interest rate would you be earning if you purchased and store the chips? (Round your final answer to two decimal places and report in percentage form: xxx%)