Suppose that the only good you purchase is hamburgers and that at the beginning of the year, the price of a hamburger is $2.00. Suppose you lend $1,000 for one year at an interest rate of 5.7 percent. At the end of the year, hamburgers cost $2.12. Calculate the real interest rate you earned on the loan. The real interest rate is %. (Round your response to one decimal place.)