Year Percent 1950 27.07846 1955 26.72627 1960 26.52013 1965 26.52175 1970 26.83207 1975 27.06707 1980 27.50563 1985 27.34629 1990 26.92469 1995 27.61219 2000 27.82659 2005 28.73465 2010 30.46017 2015 32.9906 2020 34.49885 2025 34.0944 2030 33.23303 2035 32.99321 2040 32.77317 2045 32.75878 2050 32.45329 2055 31.47559 2060 30.3833 2065 29.47501 2070 28.7513 2075 28.06097 2080 27.33077 2085 26.56034 2090 25.83914 2095 25.19183 2100 24.62343