Year Percent 1950 9.7439 1955 8.71523 1960 9.37609 1965 10.49956 1970 11.63589 1975 11.76593 1980 10.70515 1985 11.67955 1990 15.23692 1995 17.02135 2000 18.68188 2005 18.98556 2010 20.96186 2015 23.76039 2020 25.17941 2025 26.06132 2030 26.8768 2035 28.06223 2040 29.44353 2045 30.57271 2050 32.0899 2055 33.25486 2060 34.01672 2065 34.69346 2070 34.97122 2075 35.20502 2080 35.51919 2085 35.87716 2090 36.21568 2095 36.5203 2100 36.81372