Year US Dollars adjusted for inflation) 1960 1774.20574 1961 1774.50064 1962 1775.60118 1963 1825.16454 1964 1853.66169 1965 1751.37948 1966 1705.63559 1967 1887.44739 1968 1992.03716 1969 2000.58633 1970 2207.62638 1971 2310.56226 1972 2432.21187 1973 2659.33517 1974 2674.06744 1975 2635.9955 1976 2657.76284 1977 2764.15283 1978 2764.43393 1979 3041.52014 1980 2928.1285 1981 3038.3866 1982 2783.01833 1983 2605.76014 1984 2764.07048 1985 2594.70524 1986 2768.99594 1987 2574.44362 1988 2594.76348 1989 2781.21121 1990 2926.35162 1991 2820.84003 1992 2956.49941 1993 2977.50254 1994 3085.86438 1995 3122.91341 1996 3235.3573 1997 3130.72019 1998 3141.87758 1999 3392.17276 2000 3315.06747 2001 3368.93086 2002 3470.45827 2003 3501.14097 2004 3678.92578 2005 3689.06738 2006 3732.00348 2007 3667.45254 2008 3667.86084 2009 3580.39702 2010 3651.96678 2011 3719.88948 2012 3744.27711 2013 3894.26254 2014 4084.19979 2015 4211.05888 2016 4195.9681 2017 4322.98624