Year Percent 1950 12.10352 1955 13.72828 1960 12.2287 1965 11.29234 1970 11.93769 1975 12.91583 1980 15.98108 1985 16.51437 1990 17.33079 1995 18.7166 2000 23.59367 2005 21.42609 2010 23.47486 2015 31.34623 2020 31.63846 2025 30.95874 2030 28.72185 2035 27.18931 2040 27.02171 2045 26.94224 2050 27.61276 2055 28.03597 2060 27.98794 2065 28.01405 2070 27.75345 2075 27.25222 2080 26.68244 2085 26.5117 2090 26.52273 2095 26.43455 2100 26.15518