Year Percent 1950 3.63637 1955 3.62983 1960 3.66974 1965 3.71356 1970 3.76155 1975 3.80886 1980 3.86567 1985 3.94175 1990 4.22435 1995 4.51757 2000 4.55823 2005 4.76956 2010 4.90123 2015 4.83396 2020 5.03636 2025 5.42564 2030 5.97705 2035 6.57165 2040 7.22344 2045 7.95071 2050 8.76638 2055 9.66155 2060 10.56269 2065 11.39024 2070 12.39679 2075 13.57136 2080 14.63779 2085 15.59458 2090 16.50451 2095 17.45472 2100 18.48125