Year Percent 1950 11.12974 1955 11.59423 1960 11.67607 1965 11.28769 1970 11.418 1975 11.77604 1980 12.10232 1985 12.06812 1990 11.40639 1995 12.39602 2000 13.85321 2005 15.81946 2010 17.45843 2015 18.25286 2020 18.04784 2025 17.31568 2030 16.04907 2035 16.08668 2040 17.1195 2045 18.64156 2050 21.37228 2055 22.6429 2060 22.81682 2065 22.69459 2070 21.83155 2075 21.8838 2080 22.71317 2085 23.51027 2090 23.7799 2095 23.41801 2100 22.89108