Year Percent 1950 26.96748 1955 26.29605 1960 25.95601 1965 25.92587 1970 25.75162 1975 26.98388 1980 28.35398 1985 29.61469 1990 30.99836 1995 31.53824 2000 31.63614 2005 31.65112 2010 31.85416 2015 31.8314 2020 31.63778 2025 31.05856 2030 30.40032 2035 29.79246 2040 29.16795 2045 28.63108 2050 27.89067 2055 27.03904 2060 26.19831 2065 25.40644 2070 24.6784 2075 24.00365 2080 23.38471 2085 22.83279 2090 22.3481 2095 21.9387 2100 21.59949