Year US Dollars adjusted for inflation) 1960 944.29245 1961 979.77453 1962 988.7089 1963 1049.92561 1964 1119.57414 1965 1169.87963 1966 1277.54288 1967 1361.84175 1968 1506.09472 1969 1686.49158 1970 1815.01775 1971 1965.63873 1972 2067.05205 1973 2331.94299 1974 2509.2195 1975 2661.38911 1976 2962.75281 1977 3275.05015 1978 3573.22145 1979 3823.00218 1980 3699.84991 1981 3904.12801 1982 4161.98327 1983 4644.14375 1984 5066.22211 1985 5405.35428 1986 5952.54901 1987 6629.04152 1988 7345.92642 1989 7784.94135 1990 8464.93705 1991 9249.38879 1992 9719.062 1993 10279.54728 1994 11113.5131 1995 12055.23129 1996 12847.771 1997 13481.62617 1998 12652.35349 1999 13983.41283 2000 15104.52152 2001 15667.37846 2002 16734.84566 2003 17136.66157 2004 17905.22579 2005 18568.36281 2006 19427.18984 2007 20385.32004 2008 20803.50054 2009 20843.1348 2010 22086.95292 2011 22724.70557 2012 23123.76136 2013 23685.40671 2014 24323.57284 2015 24870.7709 2016 25484.03759 2017 26152.03077