Year Percent 1950 4.31677 1955 4.09477 1960 4.00014 1965 4.00503 1970 4.057 1975 4.14558 1980 4.44564 1985 4.51555 1990 4.78527 1995 4.91918 2000 4.91838 2005 5.31681 2010 5.87946 2015 6.76092 2020 7.56276 2025 8.96727 2030 10.21655 2035 11.34458 2040 11.31934 2045 15.26721 2050 16.94182 2055 19.56162 2060 21.45799 2065 22.65648 2070 24.17996 2075 25.86612 2080 27.51947 2085 28.89679 2090 30.09339 2095 31.26071 2100 32.44216