Year Percent 1950 18.29173 1955 17.70896 1960 17.0997 1965 16.59124 1970 16.34194 1975 16.47702 1980 16.73301 1985 17.47871 1990 18.1354 1995 19.74242 2000 21.76145 2005 23.6761 2010 25.4338 2015 25.98575 2020 25.90738 2025 25.8123 2030 26.0201 2035 26.35761 2040 26.49471 2045 26.05775 2050 25.14742 2055 24.24176 2060 23.67422 2065 23.35346 2070 22.99695 2075 22.72249 2080 22.42654 2085 22.16133 2090 21.95174 2095 21.81407 2100 21.70891