Year US Dollars adjusted for inflation) 1960 2829.64066 1961 2616.87435 1962 2762.64714 1963 2966.28182 1964 3064.13408 1965 2956.45217 1966 3284.39083 1967 3220.81029 1968 3381.23324 1969 3301.74698 1970 3511.84863 1971 3987.0864 1972 4137.68674 1973 4443.8728 1974 4420.57211 1975 4456.79835 1976 5078.45063 1977 4665.23288 1978 5618.90592 1979 6450.74195 1980 6120.53884 1981 5549.82339 1982 5455.59002 1983 5368.84191 1984 5577.91764 1985 6148.43451 1986 6099.42159 1987 6103.37376 1988 6408.80583 1989 7084.06687 1990 7542.55943 1991 7648.21345 1992 8158.41126 1993 8485.29143 1994 8196.09255 1995 8009.7945 1996 8281.2801 1997 9163.68507 1998 9741.3605 1999 9730.69992 2000 9790.27077 2001 9559.55196 2002 9384.15248 2003 8932.19505 2004 8709.78269 2005 9450.27943 2006 10126.29048 2007 11124.65711 2008 10645.0867 2009 10486.18989 2010 10804.68447 2011 11967.36235 2012 11999.95385 2013 12489.31485 2014 12850.49315 2015 13187.612 2016 13598.33627 2017 13997.0845