Year US Dollars adjusted for inflation) 1960 12991.26772 1961 13524.44929 1962 14224.48198 1963 14775.05916 1964 15532.63473 1965 16087.92299 1966 16764.23192 1967 17409.96594 1968 18023.81084 1969 19148.50878 1970 20058.68168 1971 20951.65281 1972 21705.16085 1973 22866.72094 1974 23652.76134 1975 23261.12808 1976 24136.13478 1977 24867.50195 1978 25770.57565 1979 26599.37664 1980 26919.19431 1981 27089.36618 1982 27633.2438 1983 27832.13868 1984 28099.07142 1985 28391.82943 1986 28887.97934 1987 29452.1407 1988 30657.64594 1989 31801.87438 1990 32543.94242 1991 32855.99599 1992 33216.009 1993 32869.77897 1994 33515.71351 1995 34091.16745 1996 34442.18439 1997 35122.74628 1998 36237.963 1999 37280.34107 2000 38460.6821 2001 38928.03031 2002 39078.1987 2003 39120.19614 2004 39915.26454 2005 40252.41822 2006 40922.08323 2007 41630.09374 2008 41478.93741 2009 40052.30512 2010 40638.334 2011 41283.1481 2012 41158.88498 2013 41183.51096 2014 41374.76125 2015 41642.31043 2016 41968.98157 2017 42567.74365