Year Percent 1950 11.61481 1955 12.26334 1960 13.01378 1965 13.59924 1970 14.2911 1975 14.90903 1980 15.19718 1985 15.55916 1990 17.69673 1995 17.23177 2000 17.46248 2005 19.25337 2010 21.61041 2015 23.22438 2020 24.71116 2025 26.35637 2030 28.11152 2035 28.68809 2040 28.93605 2045 28.55809 2050 28.8608 2055 29.884 2060 30.58572 2065 30.93588 2070 31.52393 2075 31.63182 2080 31.90716 2085 32.39728 2090 32.967 2095 33.52841 2100 34.04533