Year Percent 1950 9.31172 1955 9.92439 1960 10.1975 1965 10.53751 1970 10.79706 1975 10.88504 1980 11.26907 1985 11.62338 1990 14.6442 1995 15.06414 2000 15.04341 2005 15.8313 2010 16.8546 2015 19.11713 2020 21.54719 2025 23.76993 2030 25.43963 2035 26.87598 2040 28.11799 2045 29.47905 2050 30.56418 2055 32.13666 2060 32.91823 2065 33.60123 2070 34.71878 2075 35.6386 2080 36.38907 2085 37.0347 2090 37.56708 2095 38.04609 2100 38.54197