Year Percent 1950 5.8279 1955 5.75432 1960 6.1632 1965 7.036 1970 8.03817 1975 9.06322 1980 9.92204 1985 10.45336 1990 12.79119 1995 13.50731 2000 14.65738 2005 16.07909 2010 17.97872 2015 20.43978 2020 22.85978 2025 27.75234 2030 32.42445 2035 36.30129 2040 37.35787 2045 38.17939 2050 39.83459 2055 40.43696 2060 40.58377 2065 40.1181 2070 39.51531 2075 39.6202 2080 39.94251 2085 40.23352 2090 40.33745 2095 40.4149 2100 40.54819