Year US Dollars adjusted for inflation) 1960 538.43177 1961 481.36724 1962 510.55621 1963 537.95292 1964 546.75419 1965 539.86814 1966 599.34353 1967 599.23563 1968 625.64429 1969 652.72629 1970 601.05825 1971 708.8229 1972 800.67059 1973 817.65746 1974 820.27903 1975 797.5093 1976 784.99812 1977 827.77183 1978 852.44453 1979 883.39832 1980 898.04425 1981 897.04696 1982 876.45238 1983 854.82328 1984 837.75217 1985 842.05544 1986 870.28052 1987 889.61559 1988 912.30991 1989 922.96219 1990 930.03364 1991 913.09114 1992 877.33153 1993 853.41779 1994 849.67856 1995 861.23114 1996 871.41179 1997 851.16583 1998 855.08183 1999 851.05002 2000 833.01245 2001 841.20302 2002 823.07479 2003 824.45297 2004 843.2118 2005 868.90471 2006 900.08181 2007 935.63701 2008 912.3577 2009 917.02472 2010 967.35045 2011 998.97757 2012 1016.8066 2013 1048.23681 2014 1075.6594 2015 1107.99302 2016 1143.3644 2017 1169.34365