Year US Dollars 1960 377992440.1512 1961 639787204.25592 1962 743385132.29735 1963 510989780.2044 1964 198796024.07952 1965 -121797564.04872 1966 264594708.10584 1967 47599048.01904 1968 449391012.17976 1969 89598208.03584 1970 -632787344.25312 1971 -829138702.46085 1972 525562638.22037 1973 739193083.57349 1974 -201618837.38043 1975 -911426639.62137 1976 -433532658.69365 1977 1974471021.15915 1978 3043928242.87029 1979 5282660332.54157 1980 6468926553.67232 1981 -1744950400.38245 1982 -332135573.468 1983 3204485367.85487 1984 1547288971.04128 1985 5932933879.95375 1986 6999095311.58533 1987 10315682887.605 1988 7437930657.33348 1989 6630105712.44231 1990 6132647934.13984 1991 5137797414.2614 1992 5274193548.3871 1993 6080117513.84766 1994 3045792497.46536 1995 1026439855.53197 1996 2204079733.91017 1997 1723307291.66666 1998 1534106325.63356 1999 3454783533.84074 2000 3927202513.04072 2001 4800827608.6527 2002 4394998335.94828 2003 4150594207.30498 2004 -329307431.12296 2005 -659090194.59901 2006 -4700910273.08192 2007 -3993252438.1946 2008 -4652495849.34014 2009 1205257668.4208 2010 4659255415.0392 2011 3373591981.35969 2012 -5754515889.3531 2013 -8433692244.72033 2014 -5253780836.19195 2015 -4092686283.8903 2016 1817963899.16241 2017 4773589871.47804