Year US Dollars adjusted for inflation) 1970 42137.51899 1971 41883.14121 1972 43051.22318 1973 44201.72808 1974 44648.38222 1975 43158.00761 1976 43079.8158 1977 42958.89386 1978 42339.33407 1979 41041.86678 1980 40495.69802 1981 38896.62594 1982 37756.4209 1983 36776.51496 1984 35820.93175 1985 35095.99254 1986 34744.39245 1987 35204.98946 1988 35546.64955 1989 35831.62082 1990 35780.51967 1991 35291.71141 1992 34278.6471 1993 32766.05967 1994 32633.82513 1995 32917.64882 1996 34175.26007 1997 37293.28241 1998 38595.72321 1999 40035.48245 2000 40801.54213 2001 41420.84618 2002 42396.3024 2003 45519.49238 2004 47032.86689 2005 48831.92936 2006 49708.40049 2007 48710.66462 2008 43900.9517 2009 41979.8659 2010 39736.35406 2011 38205.77109 2012 38190.58659 2013 39104.30185 2014 40785.04923 2015 41765.92035 2016 42958.55839 2017 43942.93819