Year Percent 1950 10.28864 1955 9.92995 1960 12.04529 1965 12.98667 1970 15.14409 1975 14.62005 1980 14.49736 1985 13.53418 1990 13.2056 1995 13.98549 2000 11.4836 2005 9.05257 2010 7.96368 2015 9.16357 2020 10.86399 2025 9.61383 2030 8.38524 2035 7.49818 2040 7.06904 2045 7.03998 2050 7.16899 2055 7.19495 2060 6.88454 2065 6.40127 2070 6.06075 2075 5.9462 2080 5.97126 2085 5.99542 2090 5.90477 2095 5.71169 2100 5.50082