Year Percent 1950 13.47172 1955 14.56323 1960 15.62246 1965 17.5172 1970 16.83763 1975 15.97179 1980 17.06461 1985 18.43265 1990 19.87065 1995 21.43328 2000 22.76328 2005 23.11996 2010 23.59803 2015 24.44448 2020 25.3635 2025 26.11291 2030 26.88376 2035 27.8273 2040 28.4399 2045 28.67191 2050 28.31847 2055 26.94151 2060 25.29932 2065 23.94136 2070 23.0101 2075 22.82586 2080 22.69505 2085 22.52624 2090 22.27148 2095 22.07893 2100 22.03471