Year Percent 1950 26.99692 1955 24.75068 1960 22.30534 1965 24.93972 1970 25.1904 1975 28.69023 1980 28.15151 1985 28.78887 1990 29.23932 1995 28.98842 2000 29.11105 2005 29.31967 2010 29.44245 2015 29.84505 2020 29.82708 2025 29.37757 2030 28.3575 2035 26.44031 2040 24.39661 2045 22.71395 2050 21.46955 2055 20.92328 2060 20.452 2065 19.99715 2070 19.54132 2075 19.23168 2080 19.14683 2085 19.24365 2090 19.40581 2095 19.50949 2100 19.51503