A Swiss bank converted 5 million Swiss francs to euros to make a euro loan to a customer when the exchange rate was 1.06 Swiss francs per euro. The borrower agreed to repay the principal plus 5.75 percent interest in one year. When the loan was repaid at maturity, the exchange rate was 0.98 Swiss francs per Guro. The Swiss bank's rate of return was percent. (Round final your answer to 2 decimal places.)