Problem 9-20 Risk versus Return in T-bills (LG9-2, LG9-4) Table 9.2 Average Returns for Bonds Table 9.4 Annual Standard Deviation for T-Bills Use the tables above to caiculate the coefficient of variation of the risk-return relationship in T-bilis during each decade since 1950 . (Round your answers to 2 decimal places.) Use the tables above to calculate the coefficient of variation of the risk-return relationship in T-bilks during each decade since 1950 : (Round your answers to 2 decimal places.)