Year	US Dollars
1990	6917276270.92302
1991	8026627052.88863
1992	7932708016.57379
1993	8407257624.46064
1994	8804401933.3787
1995	9012704988.30415
1996	9820399320.68234
1997	10451878744.9805
1998	11392136682.3599
1999	12280882898.6379
2000	12588117318.498
2001	14288478433.7241
2002	14741098199.1587
2003	16891540879.3675
2004	17637831907.7007
2005	19400792777.0906
2006	20837829144.0684
2007	22374134248.4802
2008	24005530947.9011
2009	25309342666.1642
2010	26564614951.18529
2011	28098046145.1435
2012	28237091118.1225
2013	29588422319.0378
2014	32439033338.3596
2015	34893865665.484
2016	37231266354.96539
2017	40006403683.0414