Year Percent 1950 4.93602 1955 4.89681 1960 4.90922 1965 4.95529 1970 4.99681 1975 5.00754 1980 4.96013 1985 4.97882 1990 5.50138 1995 5.28608 2000 5.3389 2005 5.3622 2010 5.35243 2015 5.37913 2020 5.41335 2025 5.48113 2030 5.64399 2035 5.90977 2040 6.24132 2045 6.68348 2050 7.21461 2055 7.95337 2060 8.92612 2065 10.1037 2070 11.39634 2075 12.74674 2080 14.10581 2085 15.52871 2090 17.00074 2095 18.48825 2100 19.958