Year US Dollars adjusted for inflation) 1960 5474.62153 1961 5539.01895 1962 5384.39296 1963 5329.62514 1964 5397.71013 1965 5395.15089 1966 5502.52337 1967 5248.84142 1968 5300.41824 1969 5570.5764 1970 5670.61071 1971 5639.34366 1972 5558.67813 1973 5572.70756 1974 5730.02016 1975 6066.26498 1976 6280.02226 1977 6336.46762 1978 6633.19981 1979 6995.61218 1980 7354.22754 1981 7419.9144 1982 6652.26758 1983 5930.28403 1984 5824.94647 1985 5872.57095 1986 6349.60397 1987 6814.58134 1988 6872.38926 1989 6903.525 1990 6877.28717 1991 7070.5059 1992 7576.14609 1993 7720.4666 1994 8221.94944 1995 8044.64175 1996 8432.62114 1997 9089.1229 1998 9438.88305 1999 9207.79229 2000 8997.66012 2001 8636.54527 2002 7967.16256 2003 8036.47922 2004 8442.54956 2005 9068.23921 2006 9424.51699 2007 10014.87202 2008 10698.05201 2009 11112.45603 2010 11938.212 2011 12512.91348 2012 12913.10408 2013 13467.43784 2014 13856.69518 2015 13859.40739 2016 14042.63899 2017 14362.56121