Year Percent 1950 8.73437 1955 8.86988 1960 9.10567 1965 8.68034 1970 9.43826 1975 9.50627 1980 9.11144 1985 8.98893 1990 8.52985 1995 6.77736 2000 5.57607 2005 4.99677 2010 4.61038 2015 5.1757 2020 5.55766 2025 4.94769 2030 4.55608 2035 4.23943 2040 4.13996 2045 4.26287 2050 4.49682 2055 4.67803 2060 4.69095 2065 4.62042 2070 4.58846 2075 4.63186 2080 4.72717 2085 4.81918 2090 4.84799 2095 4.80974 2100 4.742