Year US Dollars 1965 46095238.09524 1966 78666666.66667 1967 72571428.57143 1968 122476190.47619 1969 122095238.09524 1970 -39619047.61905 1971 -5545993.4978 1972 13623978.20163 1973 -9724857.68501 1974 112027491.40894 1975 -81034054.18842 1976 -222248134.32836 1977 -430769230.76923 1978 -463959634.79097 1979 -214760147.60148 1980 -469004692.51667 1981 -713649250.70879 1982 -856441510.07279 1983 -697701826.75309 1984 -938208032.95572 1985 -507130017.97483 1986 -642065491.18388 1987 -95933389.64643 1988 36372114.71205 1989 -334983672.1795 1990 -866136363.63636 1991 -647826086.95652 1992 -1073948439.62008 1993 -1098635050.31384 1994 -459568999.60459 1995 -704240245.32092 1996 -294123690.15821 1997 -471471199.92766 1998 -640994116.0973 1999 -446720620.46872 2000 -722039833.66163 2001 -864669493.29256 2002 -873039319.12499 2003 -939774932.09158 2004 -781453231.63388 2005 -124788037.61369 2006 -647633358.37716 2007 -740518183.23708 2008 -1367015664.31296 2009 -1174109457.15767 2010 -2114643006.84644 2011 -3306151441.96619 2012 -4149817529.93149 2013 -4308980119.40666 2014 -5227955469.16416 2015 -4726855628.05873 2016 -4485986964.61825 2017 -4948334297.75978