Year Percent 1950 18.42859 1955 19.23536 1960 18.69705 1965 18.53757 1970 18.72002 1975 19.11305 1980 19.48145 1985 20.13566 1990 21.05219 1995 22.33476 2000 23.8142 2005 24.95295 2010 24.82826 2015 24.79696 2020 26.02119 2025 27.18917 2030 28.10372 2035 28.59969 2040 28.42929 2045 27.75012 2050 26.8097 2055 25.95586 2060 25.0701 2065 24.213 2070 23.49798 2075 22.93233 2080 22.64807 2085 22.66043 2090 22.70321 2095 22.63616 2100 22.43942