Year Percent 1950 15.17009 1955 15.37426 1960 15.54382 1965 14.88359 1970 14.17028 1975 14.21329 1980 14.65264 1985 15.88038 1990 16.41927 1995 17.42157 2000 19.41397 2005 21.78203 2010 25.16406 2015 25.84637 2020 26.32195 2025 26.11571 2030 25.55209 2035 25.86285 2040 26.15107 2045 26.44542 2050 26.13297 2055 25.89335 2060 25.56486 2065 25.28543 2070 25.09801 2075 24.56013 2080 24.10532 2085 23.81476 2090 23.56625 2095 23.34036 2100 23.10849