Year Percent 1950 17.63695 1955 17.24229 1960 17.10166 1965 16.74251 1970 16.47798 1975 15.91813 1980 14.85418 1985 13.8864 1990 13.74244 1995 15.36404 2000 17.27599 2005 19.31571 2010 21.51475 2015 22.76092 2020 23.76243 2025 24.50827 2030 24.93888 2035 25.38525 2040 26.09393 2045 27.26899 2050 27.85322 2055 27.73244 2060 27.24718 2065 26.43595 2070 26.17987 2075 26.31638 2080 26.33504 2085 26.09703 2090 25.67481 2095 25.27193 2100 25.0039