Year Percent 1950 4.94231 1955 4.65624 1960 4.65291 1965 4.68632 1970 4.66329 1975 4.91917 1980 4.78311 1985 4.61348 1990 4.77694 1995 4.59397 2000 4.50739 2005 4.21276 2010 4.00793 2015 4.21818 2020 4.58759 2025 4.80824 2030 4.94128 2035 4.89304 2040 5.12213 2045 5.68104 2050 6.48493 2055 7.24432 2060 7.77451 2065 8.30773 2070 9.13132 2075 10.15988 2080 11.29566 2085 12.39815 2090 13.41951 2095 14.46589 2100 15.62346