Year Percent 1950 7.6074 1955 8.15024 1960 8.99242 1965 10.05973 1970 10.91322 1975 12.43202 1980 12.37301 1985 11.43855 1990 13.4568 1995 13.94782 2000 15.09003 2005 15.45862 2010 17.33919 2015 19.82218 2020 22.87216 2025 25.75931 2030 27.71456 2035 29.35755 2040 30.13774 2045 30.79433 2050 30.9807 2055 31.20068 2060 31.36162 2065 31.77108 2070 32.21439 2075 32.70797 2080 33.18841 2085 33.63393 2090 34.03579 2095 34.40435 2100 34.76439