Assume these are the stock market and Treasury bill returns for a 5-year period:

Year		Stock Market Return (%)			T-Bill Return (%)
2011			0.98			0.03
2012			16.06			0.05
2013			33.06			0.07
2014			12.71			0.05
2015			0.67			0.21
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.) b. What was the average risk premium? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.) c. What was the standard deviation of the risk premium? (Ignore that the estimation is from a sample of data.) (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.)