Year Percent 1950 5.72309 1955 5.74289 1960 5.74635 1965 5.81304 1970 5.80965 1975 5.14971 1980 4.43619 1985 4.19124 1990 4.55773 1995 4.67161 2000 4.6435 2005 4.58491 2010 4.6069 2015 4.9554 2020 5.35564 2025 5.78502 2030 6.28088 2035 6.87964 2040 7.55987 2045 8.28671 2050 9.1335 2055 10.20201 2060 11.49581 2065 12.7797 2070 14.01375 2075 15.20536 2080 16.47932 2085 17.81241 2090 19.15493 2095 20.46959 2100 21.77167