Year Percent 1950 10.98352 1955 11.6756 1960 12.47789 1965 13.30629 1970 14.52273 1975 15.54925 1980 14.98085 1985 16.15596 1990 20.53142 1995 22.27534 2000 24.19216 2005 25.08996 2010 26.85917 2015 28.59452 2020 30.69895 2025 33.60261 2030 36.55915 2035 39.10423 2040 40.36671 2045 40.57388 2050 40.28962 2055 39.8124 2060 39.20919 2065 38.81022 2070 38.73418 2075 38.56806 2080 38.50598 2085 38.55185 2090 38.72033 2095 39.00403 2100 39.34795