Year Percent 1950 14.15081 1955 13.15553 1960 12.42636 1965 12.08358 1970 12.43073 1975 11.98468 1980 13.42352 1985 14.05047 1990 13.00712 1995 14.20468 2000 15.18219 2005 17.2033 2010 19.27754 2015 20.73217 2020 22.55855 2025 24.47468 2030 26.13091 2035 27.10865 2040 27.19206 2045 26.9145 2050 26.50192 2055 26.62432 2060 26.93525 2065 27.21176 2070 27.32389 2075 26.93714 2080 26.51087 2085 26.10173 2090 25.77242 2095 25.5143 2100 25.25904