Year US Dollars adjusted for inflation) 1966 815.50086 1967 875.53113 1968 939.69873 1969 995.36683 1970 1019.55188 1971 1053.88866 1972 1057.36821 1973 1072.54736 1974 1108.75935 1975 1166.44917 1976 1263.06424 1977 1308.01176 1978 1304.97864 1979 1334.25169 1980 1349.20785 1981 1293.49722 1982 1375.28472 1983 1361.16615 1984 1415.04943 1985 1466.72404 1986 1568.68403 1987 1531.86548 1988 1680.34999 1989 1695.42985 1990 1720.78049 1991 1811.40162 1992 1741.92089 1993 1699.40366 1994 1848.78324 1995 1722.19331 1996 1907.78645 1997 1853.01285 1998 1962.03424 1999 1958.95379 2000 1972.30029 2001 2091.23452 2002 2130.73392 2003 2230.90475 2004 2310.33845 2005 2358.44358 2006 2507.67466 2007 2566.2167 2008 2686.2283 2009 2765.85615 2010 2834.20472 2011 2942.03882 2012 2987.31592 2013 3077.31501 2014 3113.79941 2015 3209.71471 2016 3204.86465 2017 3292.44514