If the annual return on the S&P 500 index as 13.80 percent. The annual T- yield during the same period was 6.40 percent. What was the market premium during that year? 13.80% 7.40% 20.20% 6.40% If the annual return on the S&P 500 index as 13.80 percent. The annual T- yield during the same period was 6.40 percent. What was the market premium during that year? 13.80% 7.40% 20.20% 6.40%