Year Percent 1950 12.79947 1955 13.30507 1960 13.65603 1965 14.08151 1970 14.59557 1975 15.48209 1980 15.91817 1985 14.6174 1990 12.57039 1995 11.2751 2000 11.99783 2005 13.88927 2010 16.44587 2015 18.67338 2020 20.4424 2025 24.95798 2030 31.08862 2035 35.10679 2040 35.47054 2045 31.79133 2050 26.82124 2055 24.35835 2060 24.44329 2065 25.19859 2070 24.99114 2075 23.55266 2080 22.3274 2085 22.09033 2090 22.66728 2095 23.23584 2100 23.16286