Year Percent 1950 10.75684 1955 11.80509 1960 14.73901 1965 14.76678 1970 14.55516 1975 14.19942 1980 13.84541 1985 14.75196 1990 15.87883 1995 15.06209 2000 11.63029 2005 7.93455 2010 7.40996 2015 8.13136 2020 8.32647 2025 7.32835 2030 6.00508 2035 5.05858 2040 4.8063 2045 5.00963 2050 5.19733 2055 5.04701 2060 4.66318 2065 4.33198 2070 4.25696 2075 4.4219 2080 4.64163 2085 4.71623 2090 4.61796 2095 4.46387 2100 4.40727