Year US Dollars adjusted for inflation) 1960 520.40418 1961 529.29734 1962 503.59908 1963 519.13066 1964 544.42776 1965 563.14644 1966 572.45322 1967 567.38363 1968 577.30549 1969 581.61037 1970 581.23512 1971 560.18011 1972 583.05624 1973 591.05053 1974 596.65771 1975 553.93665 1976 545.14358 1977 557.93223 1978 550.4265 1979 571.07251 1980 593.61956 1981 635.11749 1982 631.52714 1983 587.28763 1984 616.0375 1985 643.58748 1986 638.74904 1987 611.02814 1988 613.23118 1989 577.53988 1990 609.34562 1991 614.00529 1992 610.5509 1993 623.95366 1994 615.12045 1995 631.17122 1996 638.07633 1997 654.54281 1998 660.63178 1999 675.67748 2000 694.24375 2001 709.46936 2002 720.16828 2003 722.6672 2004 732.33542 2005 723.19996 2006 730.27526 2007 752.21521 2008 767.03182 2009 763.15472 2010 757.69591 2011 758.57752 2012 773.18272 2013 805.96716 2014 833.64088 2015 827.83546 2016 837.19904 2017 859.95269