Year Percent 1950 23.79977 1955 23.67219 1960 20.54435 1965 19.58378 1970 20.34252 1975 21.82376 1980 23.70767 1985 24.45144 1990 25.2966 1995 27.30484 2000 28.90938 2005 30.43732 2010 31.16559 2015 30.05045 2020 30.07223 2025 29.99312 2030 29.34328 2035 27.67154 2040 24.92269 2045 22.45624 2050 21.548 2055 22.21486 2060 23.25527 2065 24.06367 2070 23.69337 2075 22.85951 2080 22.35647 2085 22.4378 2090 22.88326 2095 23.21855 2100 23.10571