Year Percent 1950 4.41223 1955 4.09171 1960 3.84341 1965 3.78231 1970 3.80602 1975 3.90239 1980 4.03596 1985 4.28941 1990 4.95145 1995 5.23743 2000 5.61493 2005 6.14465 2010 6.53172 2015 7.77263 2020 9.33886 2025 10.81426 2030 12.41673 2035 14.48763 2040 17.02912 2045 20.06506 2050 23.20459 2055 26.16256 2060 28.83016 2065 31.14892 2070 33.35285 2075 35.23608 2080 36.78602 2085 37.97271 2090 38.87595 2095 39.56363 2100 40.10546