Year Percent 1950 27.45984 1955 27.72691 1960 26.88682 1965 24.03035 1970 24.25086 1975 25.11371 1980 26.37702 1985 26.48612 1990 26.29621 1995 29.39773 2000 27.00763 2005 29.19023 2010 31.55783 2015 31.53941 2020 31.61805 2025 31.05425 2030 31.25142 2035 32.17148 2040 32.31156 2045 31.77731 2050 30.84343 2055 30.10558 2060 29.62322 2065 29.22615 2070 28.62156 2075 27.74064 2080 26.727 2085 25.77267 2090 24.98131 2095 24.30039 2100 23.64828