Year Percent 1950 8.904 1955 8.7231 1960 9.70643 1965 10.95945 1970 11.76278 1975 11.82972 1980 10.39841 1985 9.95542 1990 12.04191 1995 14.09292 2000 15.60187 2005 17.2675 2010 18.77391 2015 22.19883 2020 25.19811 2025 27.88347 2030 30.39768 2035 32.58534 2040 35.02965 2045 36.74102 2050 37.49394 2055 36.99531 2060 36.03538 2065 34.9874 2070 34.74829 2075 34.88778 2080 35.03376 2085 35.11644 2090 35.15414 2095 35.2703 2100 35.59413