Year Percent 1950 11.69505 1955 11.77836 1960 12.09221 1965 12.15841 1970 12.78206 1975 13.57719 1980 13.91809 1985 14.23898 1990 16.54672 1995 16.63997 2000 17.47641 2005 18.89552 2010 20.6639 2015 21.59278 2020 23.75088 2025 26.65358 2030 29.37882 2035 30.7936 2040 31.67811 2045 32.84636 2050 33.64351 2055 34.04437 2060 34.00344 2065 33.84172 2070 33.86673 2075 34.18299 2080 34.70512 2085 35.22785 2090 35.71995 2095 36.18143 2100 36.65737