Year Percent 1950 14.67571 1955 13.57209 1960 13.08946 1965 12.69221 1970 13.60534 1975 15.19044 1980 14.85262 1985 16.4605 1990 21.8017 1995 22.4871 2000 28.45606 2005 29.5096 2010 25.33769 2015 24.4171 2020 25.55304 2025 26.57121 2030 28.1021 2035 30.63147 2040 32.99272 2045 35.17873 2050 35.66071 2055 33.94836 2060 32.16695 2065 30.38024 2070 29.09509 2075 28.25703 2080 27.69684 2085 27.33335 2090 27.07505 2095 27.00686 2100 26.95554