Year US Dollars adjusted for inflation) 1960 3808.67656 1961 3875.26018 1962 3930.74831 1963 4118.67537 1964 4467.93353 1965 4639.44886 1966 4773.78796 1967 4902.12996 1968 5203.43592 1969 5218.09357 1970 5385.81905 1971 5412.76319 1972 5672.38382 1973 5925.77357 1974 6076.34382 1975 6237.06626 1976 6330.45132 1977 6369.9245 1978 6762.48424 1979 7235.33307 1980 7715.24412 1981 8199.23092 1982 7967.02914 1983 7468.73028 1984 7576.60838 1985 7614.33243 1986 7182.41533 1987 7173.12679 1988 7122.59472 1989 7278.50872 1990 7498.68419 1991 7661.48604 1992 7782.47221 1993 7940.14404 1994 8174.69192 1995 7522.22174 1996 7893.90733 1997 8296.16576 1998 8588.63774 1999 8694.98719 2000 8997.4335 2001 8843.90105 2002 8731.21991 2003 8749.77792 2004 8977.65771 2005 9059.81037 2006 9327.73608 2007 9392.68699 2008 9347.52416 2009 8712.14049 2010 9016.45781 2011 9207.7292 2012 9405.81305 2013 9400.322 2014 9536.60032 2015 9717.89843 2016 9871.67011 2017 9946.15799