Year Percent 1950 4.66189 1955 4.72435 1960 4.79381 1965 5.12313 1970 5.54846 1975 5.42801 1980 5.09961 1985 4.93219 1990 5.05953 1995 4.86075 2000 4.51742 2005 4.20262 2010 4.073 2015 4.34103 2020 4.66548 2025 5.02038 2030 5.43557 2035 5.93586 2040 6.51402 2045 7.10758 2050 7.78263 2055 8.64408 2060 9.71224 2065 10.79162 2070 11.85605 2075 12.91338 2080 14.08173 2085 15.34868 2090 16.67019 2095 17.99673 2100 19.34744