Year Percent 1950 9.97315 1955 9.91915 1960 9.79078 1965 9.95595 1970 10.57737 1975 11.47831 1980 12.47951 1985 13.74356 1990 17.34451 1995 17.84195 2000 18.37193 2005 19.48779 2010 21.47544 2015 23.74909 2020 26.43322 2025 29.02182 2030 30.33113 2035 31.22373 2040 31.96491 2045 32.78463 2050 33.3287 2055 34.03635 2060 34.24611 2065 34.26486 2070 34.72677 2075 35.21412 2080 35.67412 2085 36.0741 2090 36.44547 2095 36.80899 2100 37.258