Year Percent 1950 11.16315 1955 10.96653 1960 11.54607 1965 13.31962 1970 15.17216 1975 17.19391 1980 16.93162 1985 17.80949 1990 22.68405 1995 22.31063 2000 24.74867 2005 24.46144 2010 25.01042 2015 26.7746 2020 28.54305 2025 30.3415 2030 31.2798 2035 32.66947 2040 34.47752 2045 36.57289 2050 38.57088 2055 38.78665 2060 37.70469 2065 36.23603 2070 35.91554 2075 35.87426 2080 35.87028 2085 35.83211 2090 35.73018 2095 35.6675 2100 35.81695