Year Percent 1950 16.1514 1955 15.05715 1960 14.42921 1965 14.73062 1970 14.83391 1975 14.93181 1980 14.21173 1985 12.48838 1990 11.86488 1995 12.74616 2000 14.48806 2005 17.15056 2010 19.33779 2015 20.71653 2020 23.70165 2025 28.61125 2030 32.95274 2035 34.32632 2040 32.15899 2045 27.79086 2050 24.70842 2055 24.59548 2060 25.78626 2065 26.19167 2070 24.83569 2075 22.75674 2080 21.60297 2085 21.80043 2090 22.6776 2095 23.20863 2100 22.9106