Year Percent 1950 9.03597 1955 7.16347 1960 6.4832 1965 6.48289 1970 7.1191 1975 8.1589 1980 8.0857 1985 9.07705 1990 12.13687 1995 14.27063 2000 15.66794 2005 16.82622 2010 17.96548 2015 20.20231 2020 22.30067 2025 24.3892 2030 26.45953 2035 28.31522 2040 30.35866 2045 32.65803 2050 34.81665 2055 36.50265 2060 37.0757 2065 37.21576 2070 36.94163 2075 36.92922 2080 37.08224 2085 37.29661 2090 37.458 2095 37.54212 2100 37.64048