Year Percent 1950 3.8553 1955 4.36213 1960 4.74273 1965 5.04212 1970 5.37113 1975 5.64446 1980 5.81094 1985 5.96243 1990 6.44538 1995 6.50856 2000 6.59302 2005 6.95616 2010 7.47828 2015 8.8395 2020 9.42307 2025 10.29596 2030 11.52281 2035 13.20707 2040 15.44443 2045 18.12723 2050 21.26663 2055 24.74188 2060 28.48999 2065 31.93805 2070 34.6581 2075 36.25204 2080 37.69479 2085 38.96368 2090 39.90213 2095 40.42407 2100 40.66537