Year Percent 1950 6.29911 1955 5.85183 1960 5.47847 1965 5.15693 1970 4.95816 1975 4.84698 1980 4.60968 1985 4.34833 1990 4.42438 1995 4.68188 2000 4.51318 2005 4.46054 2010 4.64723 2015 4.80632 2020 5.03472 2025 5.42053 2030 5.79114 2035 6.17733 2040 7.17577 2045 8.66337 2050 10.5638 2055 12.70811 2060 14.48855 2065 16.17963 2070 18.00309 2075 20.03856 2080 22.08113 2085 24.03282 2090 25.86024 2095 27.56426 2100 29.1292