Year Percent 1950 26.94586 1955 25.18363 1960 22.43548 1965 21.94818 1970 23.77595 1975 26.47989 1980 28.11098 1985 29.32858 1990 28.42337 1995 29.33172 2000 31.16866 2005 32.84841 2010 32.28092 2015 27.60205 2020 24.46651 2025 23.1573 2030 24.08415 2035 25.54757 2040 25.96487 2045 25.10726 2050 23.5431 2055 22.45393 2060 22.33528 2065 22.85193 2070 23.33542 2075 23.2787 2080 22.68649 2085 21.96126 2090 21.50157 2095 21.43009 2100 21.55729