Year Percent 1950 26.70324 1955 28.53307 1960 32.42727 1965 29.66677 1970 26.81891 1975 27.96562 1980 29.80578 1985 33.59391 1990 34.04889 1995 30.87657 2000 28.25441 2005 28.35996 2010 30.79695 2015 32.35407 2020 31.05882 2025 28.21386 2030 25.51283 2035 24.45661 2040 24.83545 2045 24.84564 2050 23.372 2055 21.41241 2060 20.27791 2065 20.09481 2070 20.4283 2075 20.68667 2080 20.48863 2085 19.97994 2090 19.62056 2095 19.68007 2100 20.04791