Year US Dollars adjusted for inflation) 1970 19624.74976 1971 20202.43374 1972 20970.62643 1973 21903.40351 1974 22089.74897 1975 21980.08789 1976 23167.05926 1977 23996.77291 1978 24740.23653 1979 25755.65781 1980 26064.38931 1981 26162.45463 1982 26083.95215 1983 26563.64494 1984 27408.09981 1985 28108.89301 1986 28738.68261 1987 29096.91018 1988 30057.94148 1989 30988.58946 1990 32337.10102 1991 33742.21922 1992 34130.8524 1993 33583.00604 1994 34289.12475 1995 34782.56863 1996 34965.69089 1997 35560.20929 1998 36258.67443 1999 36955.28961 2000 37998.42531 2001 38577.72563 2002 38512.92004 2003 38218.34965 2004 38673.88811 2005 38969.3217 2006 40456.85738 2007 41831.86709 2008 42365.0975 2009 40086.10476 2010 41785.55691 2011 44125.33141 2012 44259.25991 2013 44354.73689 2014 45022.56535 2015 45412.55681 2016 45923.00757 2017 46747.19247