Year Percent 1950 4.52297 1955 4.71874 1960 4.8928 1965 5.05155 1970 5.0496 1975 4.78554 1980 4.76953 1985 5.25649 1990 6.55411 1995 7.22347 2000 7.7271 2005 8.22757 2010 8.6266 2015 9.95194 2020 11.86688 2025 13.91281 2030 15.74468 2035 17.52568 2040 19.46037 2045 21.81481 2050 24.04034 2055 26.1883 2060 27.71257 2065 29.09627 2070 30.50056 2075 32.31646 2080 33.83542 2085 35.05167 2090 36.02054 2095 36.84325 2100 37.6257