Year Percent 1950 10.3015 1955 8.46982 1960 9.09547 1965 8.42852 1970 8.6754 1975 8.21298 1980 8.10465 1985 7.46114 1990 7.43394 1995 6.69119 2000 5.45617 2005 5.15899 2010 4.98033 2015 4.89574 2020 5.22315 2025 4.62593 2030 4.10968 2035 3.82951 2040 3.8471 2045 3.99249 2050 4.17069 2055 4.24296 2060 4.17221 2065 4.07906 2070 4.08887 2075 4.21475 2080 4.38098 2085 4.49606 2090 4.51671 2095 4.46984 2100 4.42752