Year Percent 1950 9.24522 1955 8.64168 1960 8.23411 1965 7.46611 1970 6.67883 1975 5.7072 1980 4.57429 1985 4.03247 1990 5.34813 1995 5.52631 2000 5.938 2005 5.78719 2010 5.45065 2015 6.29943 2020 7.63527 2025 9.13592 2030 10.23967 2035 11.47949 2040 12.87206 2045 14.76156 2050 17.28257 2055 19.74914 2060 21.03343 2065 21.53948 2070 22.73078 2075 24.42307 2080 26.03757 2085 27.21892 2090 28.04686 2095 28.83878 2100 29.75697