Year	US Dollars
1990	4335858264.83865
1991	-1375396106.964
1992	1415829139.46152
1993	954189914.57702
1994	2272176354.11625
1995	3187628865.97938
1996	-2057416267.94258
1997	-5975055652.12088
1998	-8190136387.17845
1999	-9797080991.15223
2000	-10885161409.0794
2001	-6888297222.69718
2002	-6771078431.37255
2003	-5774343678.48602
2004	-6845745844.26947
2005	-3231339823.82941
2006	-7113624645.52718
2007	-15158062068.7164
2008	-26906857047.9827
2009	-3769109964.42424
2010	-9577156501.84061
2011	-10345956527.609
2012	-2202978658.06844
2013	10211035879.2634
2014	7858614677.44492
2015	14771455100.1459
2016	19079080856.2443
2017	20952028153.36169