Year Percent 1950 29.01688 1955 26.94557 1960 25.66374 1965 25.74154 1970 27.09983 1975 28.01401 1980 28.77613 1985 29.14144 1990 28.72621 1995 28.72044 2000 27.88329 2005 25.60666 2010 24.43055 2015 24.18445 2020 24.40708 2025 24.99168 2030 25.01998 2035 23.67977 2040 22.89945 2045 22.79702 2050 22.82143 2055 23.2827 2060 23.38822 2065 23.03303 2070 22.50461 2075 22.13106 2080 22.00649 2085 22.04308 2090 22.05342 2095 21.88649 2100 21.56957