Year US Dollars adjusted for inflation) 1965 1785.34249 1966 1898.05095 1967 1996.99463 1968 2067.15195 1969 2145.75223 1970 2381.25035 1971 2414.82701 1972 2458.35342 1973 2594.76933 1974 2798.91413 1975 2983.40118 1976 3142.5733 1977 3336.48245 1978 3563.48866 1979 3798.06157 1980 3938.53276 1981 4112.12084 1982 4159.06363 1983 4300.02486 1984 4494.83905 1985 4675.78666 1986 4255.56226 1987 4274.68354 1988 4467.7103 1989 4135.3731 1990 3524.77875 1991 2761.55506 1992 1509.87727 1993 1059.31042 1994 958.80622 1995 1010.25068 1996 1152.09156 1997 1297.02319 1998 1350.49669 1999 1400.10402 2000 1436.8795 2001 1516.87988 2002 1610.70725 2003 1812.11176 2004 1943.5587 2005 2158.09453 2006 2391.41465 2007 2722.15153 2008 2821.08074 2009 2753.63927 2010 2964.47703 2011 3220.39135 2012 3469.6717 2013 3633.74088 2014 3851.72342 2015 3973.21935 2016 4083.99816 2017 4290.16785