Year US Dollars adjusted for inflation) 1960 1038.93255 1961 903.12577 1962 1067.05938 1963 1094.00646 1964 1039.40291 1965 1021.60854 1966 1060.78109 1967 1020.81586 1968 1034.91831 1969 1099.73364 1970 1066.82856 1971 1100.48242 1972 1073.06448 1973 1129.93568 1974 1134.36376 1975 1048.60913 1976 965.25848 1977 944.98628 1978 869.12856 1979 848.8108 1980 844.54953 1981 842.59842 1982 818.22934 1983 809.69551 1984 833.53298 1985 816.0797 1986 832.2303 1987 831.62437 1988 811.98931 1989 777.24287 1990 702.08295 1991 619.68274 1992 533.35988 1993 443.84366 1994 411.28179 1995 400.99743 1996 385.99283 1997 355.50414 1998 341.8498 1999 319.70793 2000 290.16769 2001 276.33733 2002 276.25489 2003 282.84261 2004 292.54195 2005 300.75145 2006 306.71818 2007 315.45883 2008 324.24209 2009 322.62049 2010 334.23174 2011 345.48122 2012 357.81641 2013 375.44427 2014 397.58202 2015 411.27914 2016 407.56371 2017 409.11737