Year current US$ 1960 8.724514721997519 1961 23.064279414451782 1962 66.22644269968612 1963 27.847462362294664 1964 12.53986407800385 1965 27.429185066041335 1966 28.750714098130143 1967 18.947239283410457 1968 11.752826417090827 1969 11.48063814617748 1970 8.807273990475846 1971 8.490615040175593 1972 8.377703916892722 1973 6.5015602871888944 1974 8.9406333103482 1975 11.970338106043554 1976 15.397309418703657 1977 18.44926561054787 1978 25.575812593506146 1979 42.85639495140027 1980 50.22852713802871 1981 54.3753059227347 1982 52.89602059315922 1983 55.59108854700304 1984 60.026839604394084 1985 40.4022986152622 1986 41.99734430446367 1987 32.91956896612787 1988 26.323567224783297 1989 23.979103951234325 1990 51.472327565558885 1991 81.28459088157038 1992 58.26682428953009 1993 57.35730738605082 1994 29.832515147237526 1995 57.458333826912245 1996 78.34512790530572 1997 31.758487157053796 1998 27.2769563567812 1999 33.676936172343545 2000 23.28662589455783 2001 12.905614459599624 2002 17.96707170016941 2003 34.61070052774902 2004 68.34063136688886 2005 67.99399089062699 2006 75.50796729351475 2007 81.19766380767767 2008 329.24081998055175 2009 119.91090797585112 2010 352.2700212021127 2011 182.30630328976477 2012 130.8273400464146 2013 121.0508479241881 2014 165.86059179905575 2015 237.2900894401722 2016 174.06780877567567 2017 131.67367405486664 2018 121.47729895339339 2019 116.58701646045495 2020 128.2357152519803 2021 116.74974950780835 2022 91.41602144273811