Year Percent 1950 5.46905 1955 4.68933 1960 4.47071 1965 4.53486 1970 4.61416 1975 4.98315 1980 4.92539 1985 4.7738 1990 5.12845 1995 5.44233 2000 6.03484 2005 6.58197 2010 6.89592 2015 7.05611 2020 7.91126 2025 9.60149 2030 11.68278 2035 13.76405 2040 16.33154 2045 19.18667 2050 22.03797 2055 24.80486 2060 27.58712 2065 30.24619 2070 32.41851 2075 34.26071 2080 35.86294 2085 37.16589 2090 38.15206 2095 38.8267 2100 39.26147