Year Percent 1950 16.07843 1955 14.61479 1960 13.30086 1965 12.24327 1970 11.68465 1975 11.34522 1980 10.70774 1985 9.91476 1990 9.80262 1995 10.30004 2000 10.74687 2005 11.21194 2010 11.7225 2015 12.76263 2020 14.29291 2025 16.05915 2030 17.61054 2035 18.45609 2040 19.31756 2045 20.14256 2050 21.10363 2055 22.02733 2060 22.62529 2065 23.0331 2070 23.31158 2075 23.72879 2080 24.09375 2085 24.35151 2090 24.49759 2095 24.55768 2100 24.57581