Year Percent 1950 10.2451 1955 9.94587 1960 9.58885 1965 9.56527 1970 9.958 1975 10.71294 1980 11.52102 1985 12.58423 1990 15.52684 1995 16.08533 2000 16.66421 2005 17.87415 2010 19.95796 2015 22.37901 2020 25.17176 2025 27.83443 2030 29.17145 2035 30.02664 2040 30.69467 2045 31.45311 2050 31.96582 2055 32.71824 2060 32.98827 2065 33.03838 2070 33.50393 2075 33.99411 2080 34.46253 2085 34.875 2090 35.25664 2095 35.62937 2100 36.07495