Year Percent 1950 29.47541 1955 29.50245 1960 29.41509 1965 29.21707 1970 28.81146 1975 27.77583 1980 26.67968 1985 25.87122 1990 25.72836 1995 26.51761 2000 27.48469 2005 28.4031 2010 28.95128 2015 29.3759 2020 30.04258 2025 30.92266 2030 32.06322 2035 32.85321 2040 33.22563 2045 33.20303 2050 32.85772 2055 32.49681 2060 32.06323 2065 31.54292 2070 30.96267 2075 30.37847 2080 29.79361 2085 29.23494 2090 28.69083 2095 28.15748 2100 27.65757