Year Percent 1950 1.66296 1955 2.14308 1960 2.77377 1965 3.08332 1970 3.35232 1975 3.54372 1980 3.69831 1985 3.82349 1990 4.10951 1995 4.24511 2000 4.33142 2005 4.41867 2010 4.38504 2015 4.26041 2020 4.18585 2025 4.16484 2030 4.16128 2035 4.16221 2040 4.22071 2045 4.33361 2050 4.47065 2055 4.72934 2060 5.16657 2065 5.76634 2070 6.50272 2075 7.35462 2080 8.32293 2085 9.41644 2090 10.62988 2095 11.94896 2100 13.35399