Year Percent 1950 15.50508 1955 16.32993 1960 14.59781 1965 13.80912 1970 14.14134 1975 15.40807 1980 16.23422 1985 16.60052 1990 16.4602 1995 16.47921 2000 17.22248 2005 18.71755 2010 20.46904 2015 22.14266 2020 23.98641 2025 25.2831 2030 26.05992 2035 26.29569 2040 26.46585 2045 26.35056 2050 26.26197 2055 26.27965 2060 25.9309 2065 25.50174 2070 25.02698 2075 24.47978 2080 24.02509 2085 23.72005 2090 23.52317 2095 23.31886 2100 23.08909