Year US Dollars 1960 0 1961 -105052154.86841 1962 -134006459.03708 1963 -137718549.31512 1964 -169085712.16452 1965 -83769633.50785 1966 -88038911.45552 1967 125271857.32927 1968 146258894.67716 1969 281442825.25929 1970 292796868.06047 1971 188058850.17363 1972 453610805.82834 1973 506946468.47372 1974 449956276.33357 1975 561881990.59815 1976 1375183493.72044 1977 1027027027.02703 1978 185750581.80498 1979 291242728.92638 1980 -149112758.98796 1981 -471436494.731 1982 182210580.07545 1983 539833727.90838 1984 2681760040.93118 1985 3583970837.39796 1986 3739315417.83604 1987 5271661772.43759 1988 5329490135.79297 1989 7885357504.58339 1990 6568076202.21315 1991 6048872760.96356 1992 5422318683.30622 1993 8119344330.11014 1994 1571606024.53289 1995 -6481941104.99237 1996 -2371384611.40633 1997 -5954327637.20438 1998 905452338.83775 1999 8561650016.11344 2000 7568667214.29305 2001 7945709596.34819 2002 13569221300.4398 2003 14681640725.3301 2004 14729840780.6882 2005 22181734020.8041 2006 21601869255.1301 2007 22588766118.9017 2008 22308522114.3474 2009 16850924946.464 2010 13431627451.9898 2011 9568088386.43371 2012 2969289876.74688 2013 1654461062.4033 2014 597361395.90668 2015 7391960576.89827 2016 7348337477.2941 2017 3107452651.0291