Year Percent 1950 28.25671 1955 28.80707 1960 28.5136 1965 27.75289 1970 26.80592 1975 25.70464 1980 24.88117 1985 25.90186 1990 27.97659 1995 30.31939 2000 32.2191 2005 33.35447 2010 34.17644 2015 34.71697 2020 34.46598 2025 33.6653 2030 32.36553 2035 30.96755 2040 29.44471 2045 27.82956 2050 26.458 2055 25.16842 2060 23.90565 2065 22.80371 2070 21.9141 2075 21.24361 2080 20.75573 2085 20.37813 2090 20.09272 2095 19.88803 2100 19.75199