Year 2006 2007 2008 2009 2010 SLUCK Vidi Kel Return 15.97 5.91 -37.53 28.60 17.46 T-Bill Return 5.00 4.86 1.90 0.30 0.32 a. What was the risk premium on common stock in each year? (Negative values should be indicated by a minus sign. Round your answers to 2 decimal places.) Year 2006 2007 2008 2009 2010 Risk Premium 10.97% % % 28.20 % 17.04 % b. What was the average risk premium? (Do not round intermediate calculations. Round your answer to 2 decimal places.) Average risk premium % c. What was the standard deviation of the risk premium? (Do not round intermediate calculations. Round your answer to 2 decimal places.) Standard deviation of the risk % premium