Year Percent 1950 29.16459 1955 30.94724 1960 32.73256 1965 31.23822 1970 32.00977 1975 29.33247 1980 28.03837 1985 26.48898 1990 28.74428 1995 27.16396 2000 27.03352 2005 27.26437 2010 27.14852 2015 27.60442 2020 28.15047 2025 29.01708 2030 30.15873 2035 31.31519 2040 32.13752 2045 32.65606 2050 32.94257 2055 33.0003 2060 32.90939 2065 32.63858 2070 32.18143 2075 31.58749 2080 30.94762 2085 30.34214 2090 29.80914 2095 29.33376 2100 28.8722