Suppose we have the following returns for large-company stocks and Treasury bills over a six year period: Year Large Company US Treasury Bill 1 3.66 4.66 2 14.44 2.33 3 19.03 4.12 4 –14.65 5.88 5 –32.14 4.90 6 37.27 6.33 c-2 Calculate the observed risk premium in each year for the large-company stocks versus the T-bills. What was the standard deviation of the risk premium over this period? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.)