Assume these are the stock market and Treasury bill returns for a 5-year period: Year 2013 2014 2015 2016 2017 Stock Market Return (%) 31.7 10.9 -1.6 13.0 21.3 T-Bill Return (%) 0.02 0.02 0.02 0.20 0.80 Required: a. What was the risk premium on common stock in each year? (Negative values should be entered with a negative sign.) b. What was the average risk premium? c. What was the standard deviation of the risk premium? (Ignore that the estimation is from a sample of data.) Complete this question by entering your answers in the tabs below. Required A Required B Required C What was the risk premium on common stock in each year? (Do not round intermediate calculations. Enter your answers as a percent rounded to 2 decimal places.) Year Risk Premium 2013 % 2014 % 2015 % 2016 % 2017 %