Year Percent 1950 13.83518 1955 12.86717 1960 14.93599 1965 15.58556 1970 16.33544 1975 16.12732 1980 15.82385 1985 14.17959 1990 14.3441 1995 12.97621 2000 10.22308 2005 10.86478 2010 8.36333 2015 8.04241 2020 8.31613 2025 8.06485 2030 7.08239 2035 6.51704 2040 6.32144 2045 6.25838 2050 6.25304 2055 6.17087 2060 5.98918 2065 5.80523 2070 5.71278 2075 5.69653 2080 5.69435 2085 5.65204 2090 5.56525 2095 5.46495 2100 5.39245