You've observed the following returns on Leo's Lightbulbs stock over the past five years: 15 percent, -3 percent, 18 percent, 11 percent, and -1 percent. Suppose the average T-bill rate over this period was 5.6 percent. What was the average risk premium of this stock over the five-year period? Hint: Be sure to use the arithmetic average. (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g. 1.23. Do not input a percent sign with your answer.)