Year Percent 1950 27.38798 1955 27.91491 1960 27.29685 1965 26.3621 1970 26.29884 1975 27.1166 1980 28.6084 1985 30.80668 1990 32.00979 1995 32.26117 2000 32.29092 2005 31.76991 2010 31.74064 2015 31.74131 2020 31.21495 2025 30.48585 2030 29.52709 2035 28.78545 2040 28.14668 2045 27.41148 2050 26.57321 2055 25.68852 2060 24.85474 2065 24.11589 2070 23.44134 2075 22.84231 2080 22.31362 2085 21.85197 2090 21.46939 2095 21.14934 2100 20.88451