Assume these are the stock market and Treasury bill returns for a 5-year period: Year 2011 2012 2013 2014 2015 Stock Market Return (%) -32.93 32.80 13.56 4.98 20.76 T-Bill Return (%) 5.10 1.40 0.32 0.09 0.11 a. 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 2011 Risk Premium (38.03) % 31.40% 13.24% 2012 2013 2014 4.89% 2015 20.65%