Year Percent 1950 21.26831 1955 22.33452 1960 22.42067 1965 22.08897 1970 20.74833 1975 18.27071 1980 17.18215 1985 17.05993 1990 19.43726 1995 22.05028 2000 23.77721 2005 24.89561 2010 24.79235 2015 26.31744 2020 27.78805 2025 28.32117 2030 27.55183 2035 25.02245 2040 22.6594 2045 21.43365 2050 22.23966 2055 23.76364 2060 24.51068 2065 24.15566 2070 23.01227 2075 22.14391 2080 22.04578 2085 22.43169 2090 22.77254 2095 22.68051 2100 22.1942