Andrew plans to leave in 40 years. He is thinking of investing his retirement funds in stocks, so he seeks out information on past returns. He learns that over the 101 years from the 1900 to 2000, the real (that is, adjusted for inflation) returns on U.S. common stocks had mean 8.7% as well as standard deviation 20.2%. The distribution of annual returns on common stocks is roughly symmetric. What sample mean annual return (sample mean for the next 40 years before Andrew retires) would be higher than 80% of all samples mean annual returns?