Year Percent 1950 17.46454 1955 17.10424 1960 17.00474 1965 16.67593 1970 16.40422 1975 15.81899 1980 14.68148 1985 13.72215 1990 13.57234 1995 15.03724 2000 16.87589 2005 18.78158 2010 20.89801 2015 22.22833 2020 23.34721 2025 24.26591 2030 24.79558 2035 25.33776 2040 26.13124 2045 27.36116 2050 28.03359 2055 27.96774 2060 27.52635 2065 26.75995 2070 26.56284 2075 26.7734 2080 26.86102 2085 26.67882 2090 26.30216 2095 25.93971 2100 25.7097