Year Percent 1950 9.17353 1955 10.23853 1960 10.18889 1965 8.9068 1970 8.60387 1975 8.18988 1980 8.27392 1985 8.31852 1990 7.40983 1995 6.53944 2000 5.31909 2005 4.77365 2010 4.56766 2015 5.24108 2020 5.40716 2025 5.15825 2030 4.78834 2035 4.4796 2040 4.4328 2045 4.6662 2050 4.95995 2055 5.07856 2060 4.99767 2065 4.86177 2070 4.82529 2075 4.93178 2080 5.09262 2085 5.1862 2090 5.14116 2095 5.01512 2100 4.90715