Year Percent 1950 21.1928 1955 21.25224 1960 19.57535 1965 20.81853 1970 22.71413 1975 24.66671 1980 26.20488 1985 24.39538 1990 24.00718 1995 24.77017 2000 26.00893 2005 27.23265 2010 27.32176 2015 26.13368 2020 26.22122 2025 26.51376 2030 27.02169 2035 26.77441 2040 26.02608 2045 25.5749 2050 24.54975 2055 23.83783 2060 23.53864 2065 23.2561 2070 23.26921 2075 23.23093 2080 23.05179 2085 22.81264 2090 22.64117 2095 22.56164 2100 22.50617