Year Percent 1950 29.60988 1955 27.71745 1960 26.14961 1965 24.3394 1970 21.18925 1975 24.2151 1980 26.8948 1985 31.01433 1990 32.49304 1995 34.46821 2000 33.63351 2005 36.33657 2010 35.4823 2015 31.76544 2020 28.56028 2025 25.5887 2030 24.57095 2035 25.50114 2040 27.03067 2045 27.90017 2050 27.40728 2055 25.874 2060 25.06199 2065 25.13562 2070 25.34906 2075 25.09905 2080 24.35587 2085 23.44621 2090 22.80583 2095 22.559 2100 22.53369