Suppose the S&R index is 800, the continuously compounded risk free rat is 5 %, and the dividend yield is 0%. A 1-year 815-strike European call costs $75 and a 1-year 815-strike European call costs $75 and a 1-year 815-strike European put costs $45. Consider the strategy of buying the stock, selling the 815-strike call, and buying the 815-strike put. a. What is the rate of return on this position held until the expiration of the options? Round your answer to four digits and enter as a number not as a percent.