Year Percent 1950 28.71554 1955 28.71985 1960 27.12155 1965 26.36059 1970 25.6604 1975 25.45914 1980 25.93253 1985 26.02324 1990 26.06498 1995 25.83255 2000 26.07663 2005 26.61775 2010 27.06068 2015 27.53391 2020 28.08393 2025 28.87903 2030 29.7221 2035 30.4036 2040 30.96019 2045 31.34262 2050 31.60278 2055 31.74941 2060 31.75986 2065 31.62446 2070 31.36367 2075 31.02093 2080 30.62059 2085 30.16435 2090 29.66463 2095 29.1313 2100 28.57948