Year Percent 1950 15.4789 1955 16.1567 1960 17.14204 1965 18.10712 1970 18.7816 1975 18.9329 1980 17.53241 1985 18.1138 1990 23.3115 1995 24.09225 2000 24.63667 2005 24.6317 2010 25.59082 2015 26.22356 2020 27.62982 2025 29.33313 2030 30.79357 2035 31.8586 2040 32.65579 2045 33.37911 2050 33.85202 2055 34.13219 2060 34.00992 2065 33.95117 2070 34.25767 2075 34.6199 2080 35.05465 2085 35.45975 2090 35.83339 2095 36.22332 2100 36.69753