Year Percent 1950 3.97531 1955 3.74189 1960 4.31654 1965 5.01355 1970 5.37223 1975 6.11629 1980 5.5431 1985 5.49465 1990 6.53245 1995 7.65844 2000 8.39185 2005 8.8261 2010 9.35616 2015 10.14342 2020 11.27097 2025 13.08725 2030 15.04109 2035 17.25784 2040 19.74684 2045 22.24333 2050 24.44809 2055 26.40544 2060 28.41564 2065 30.16112 2070 31.65038 2075 33.0224 2080 34.16427 2085 35.06287 2090 35.74839 2095 36.31704 2100 36.80535