Year Percent 1950 29.88737 1955 29.53142 1960 27.87367 1965 25.85404 1970 25.68967 1975 25.44862 1980 26.03278 1985 27.39892 1990 27.47938 1995 28.0044 2000 29.30368 2005 31.0804 2010 32.80404 2015 32.23482 2020 30.69499 2025 29.18471 2030 27.90802 2035 28.99272 2040 29.82847 2045 29.87836 2050 29.50515 2055 28.19045 2060 27.66393 2065 27.56768 2070 27.4693 2075 27.014 2080 26.23984 2085 25.49636 2090 24.90758 2095 24.44245 2100 24.0011