Year Percent 1950 11.83626 1955 12.59014 1960 14.04907 1965 15.62836 1970 17.11548 1975 18.6123 1980 16.70203 1985 18.07068 1990 21.92235 1995 22.80576 2000 23.67641 2005 25.03104 2010 25.83915 2015 28.87799 2020 30.73397 2025 31.13976 2030 32.14516 2035 34.1581 2040 36.59172 2045 37.39196 2050 37.9744 2055 39.05078 2060 38.9856 2065 38.64249 2070 38.44386 2075 38.04967 2080 37.84985 2085 37.82135 2090 37.89136 2095 37.97274 2100 38.10801