Year US Dollars 1960 37777799.54785 1961 -38069179.10448 1962 -188604.88031 1963 -17774811.11111 1964 -41462555.55556 1965 58952380.95238 1966 -161562962.96296 1967 29565648.97599 1968 -77333857.11743 1969 -73439673.93501 1970 -108435117.81482 1971 -301003797.66521 1972 -45731614.73839 1973 84847465.39282 1974 -115111466.25124 1975 226335736.80381 1976 489984072.63294 1977 707017389.90923 1978 665046865.32805 1979 493556626.23419 1980 211513679.63738 1981 -1303010477.30559 1982 -1654032419.03823 1983 -1077894025.2988 1984 -228134899.19905 1985 449716834.24483 1986 2391414016.62096 1987 1467395338.21613 1988 952624924.08246 1989 1654613520.46584 1990 2313543192.37049 1991 3066108773.71456 1992 961623286.13439 1993 -1300418946.85915 1994 -4837512137.65192 1995 -5947981744.62857 1996 -5484866733.01492 1997 -6307822629.07108 1998 -5802491966.42256 1999 468747716.54879 2000 -835856910.68531 2001 -3070668019.8709 2002 -3282237494.35379 2003 -3186689303.7727 2004 -2718389459.61796 2005 -2835187451.13287 2006 -4713402351.42406 2007 -6744000048.50137 2008 -6033913613.24194 2009 -5187058680.11296 2010 -5249214987.95726 2011 -4013766276.8422 2012 -6574671354.08345 2013 -9710585801.3759 2014 -20599156451.1802 2015 -23683742061.88169 2016 -19467135183.2509 2017 -16435316529.0981