Year Percent 1950 9.93717 1955 9.98096 1960 11.07646 1965 12.50026 1970 13.66383 1975 14.50564 1980 13.01298 1985 13.92146 1990 16.82193 1995 17.47782 2000 17.97572 2005 19.0243 2010 20.81967 2015 23.73954 2020 26.37592 2025 28.47887 2030 29.94526 2035 32.03558 2040 34.78322 2045 37.05802 2050 38.88671 2055 39.92999 2060 39.65226 2065 38.87681 2070 38.51375 2075 38.29721 2080 38.21531 2085 38.21904 2090 38.17405 2095 38.07458 2100 38.10838