Year Percent 1950 4.75481 1955 4.31477 1960 4.14145 1965 4.05934 1970 4.06633 1975 4.17986 1980 4.37834 1985 4.64401 1990 5.07507 1995 5.22078 2000 5.32818 2005 5.20626 2010 5.0898 2015 5.21993 2020 5.45259 2025 5.75029 2030 6.12933 2035 6.65317 2040 7.30159 2045 8.05989 2050 8.80181 2055 9.56372 2060 10.61564 2065 11.89611 2070 13.22777 2075 14.53913 2080 15.88121 2085 17.26468 2090 18.67155 2095 20.08547 2100 21.4942