Year Percent 1950 6.75662 1955 7.184 1960 8.02659 1965 8.04163 1970 7.35053 1975 6.18657 1980 5.90523 1985 6.09314 1990 6.37366 1995 7.01393 2000 6.83468 2005 6.32571 2010 5.86254 2015 5.68132 2020 5.88621 2025 5.81304 2030 5.68966 2035 5.58665 2040 5.48834 2045 5.45124 2050 5.49487 2055 5.55063 2060 5.54846 2065 5.501 2070 5.43 2075 5.36229 2080 5.3161 2085 5.28816 2090 5.25104 2095 5.19696 2100 5.12019