Calculate the average returns for the S\&P 500 stock index, High-Grade Corporate Bonds, or the U.S. Treasury Bond from 1928 to 2021 . Note: Round your answers to 2 decimal places. Calculate the standard deviation of returns to the S\&P 500 stock index, High-Grade Corporate Bonds, or the U.S. Treasury Bond from 1928 to 2021 . Note: Round your answers to 2 decimal places. Calculate the average returns for the S\&P 500 stock index, High-Grade Corporate Bonds, or the U.S. Treasury Bond from 1928 to 2021 . Note: Round your answers to 2 decimal places. Calculate the standard deviation of returns to the S\&P 500 stock index, High-Grade Corporate Bonds, or the U.S. Treasury Bond from 1928 to 2021 . Note: Round your answers to 2 decimal places