Year Percent 1950 4.52347 1955 4.74381 1960 4.89487 1965 4.98247 1970 5.01441 1975 5.0327 1980 4.86208 1985 4.64291 1990 4.66373 1995 4.35133 2000 4.27637 2005 4.25551 2010 4.28428 2015 4.32802 2020 4.3757 2025 4.39471 2030 4.46822 2035 4.57104 2040 4.68197 2045 4.88725 2050 5.25095 2055 5.74609 2060 6.42099 2065 7.10962 2070 7.87806 2075 8.69935 2080 9.64008 2085 10.64429 2090 11.69923 2095 12.78805 2100 13.89715