Year US Dollars adjusted for inflation) 1960 2684.23958 1961 2801.07316 1962 2995.22985 1963 3036.24848 1964 3143.44213 1965 3226.72143 1966 3394.98509 1967 3427.95902 1968 3338.78147 1969 3362.11576 1970 3381.86402 1971 3443.35033 1972 3469.88223 1973 3591.92384 1974 3827.05749 1975 3887.57552 1976 3840.45707 1977 3752.74386 1978 3558.36473 1979 3609.02125 1980 3727.84387 1981 3838.96267 1982 3739.37287 1983 3272.13086 1984 3312.24996 1985 3303.48772 1986 3533.28887 1987 3790.60272 1988 3357.50254 1989 2880.89101 1990 2679.93479 1991 2683.29267 1992 2615.50889 1993 2699.56254 1994 2975.98055 1995 3140.77219 1996 3175.53562 1997 3328.59547 1998 3266.57326 1999 3268.51096 2000 3310.77999 2001 3287.28578 2002 3422.23835 2003 3520.27532 2004 3649.37205 2005 3831.36485 2006 4069.7771 2007 4362.94899 2008 4703.07993 2009 4695.67517 2010 5022.49319 2011 5270.94875 2012 5520.55917 2013 5765.88714 2014 5825.19849 2015 5937.28535 2016 6094.73825 2017 6172.69359