Year US Dollars adjusted for inflation) 1960 304.71069 1961 315.39375 1962 321.59842 1963 340.93167 1964 357.54282 1965 384.75433 1966 396.53513 1967 407.03329 1968 424.96506 1969 436.47668 1970 473.07741 1971 462.58108 1972 453.79056 1973 472.58623 1974 475.65377 1975 481.45746 1976 491.38136 1977 495.42293 1978 518.85173 1979 521.44874 1980 556.31062 1981 580.81674 1982 598.40312 1983 617.85002 1984 627.81996 1985 653.57982 1986 667.49758 1987 688.22187 1988 717.94598 1989 731.12073 1990 741.80145 1991 757.86886 1992 794.62099 1993 787.79411 1994 796.63057 1995 815.33594 1996 833.7471 1997 821.66182 1998 822.44304 1999 832.69779 2000 848.63178 2001 846.64237 2002 855.49855 2003 878.44152 2004 923.9233 2005 974.5373 2006 1013.76537 2007 1041.28938 2008 1037.57514 2009 1045.20793 2010 1040.14227 2011 1046.49355 2012 1060.50137 2013 1083.96701 2014 1111.19596 2015 1140.20627 2016 1179.41401 2017 1222.52391