Year Percent 1950 29.18878 1955 26.96209 1960 25.25187 1965 24.59934 1970 25.35271 1975 27.59737 1980 29.313 1985 31.4404 1990 31.42814 1995 31.35281 2000 29.34557 2005 27.97633 2010 26.88751 2015 26.10952 2020 26.15621 2025 25.56284 2030 25.01303 2035 24.2375 2040 23.87798 2045 23.87114 2050 23.54102 2055 23.21556 2060 22.85076 2065 22.47681 2070 22.13679 2075 21.86236 2080 21.61432 2085 21.36113 2090 21.10368 2095 20.84732 2100 20.61194