Year Percent 1950 13.35271 1955 12.20589 1960 11.10602 1965 11.18399 1970 11.84241 1975 12.08699 1980 11.4622 1985 10.39307 1990 10.20395 1995 11.26576 2000 11.69985 2005 12.87866 2010 12.85912 2015 13.02683 2020 13.86089 2025 15.57432 2030 17.96196 2035 18.90556 2040 19.8433 2045 20.43145 2050 21.35647 2055 22.98372 2060 24.06969 2065 24.65341 2070 24.85021 2075 25.12402 2080 25.54791 2085 25.97277 2090 26.15525 2095 26.01061 2100 25.66314