Year	US Dollars
1990	3242754960.86737
1991	3325601775.70863
1992	3275931332.01341
1993	2832799817.7742
1994	3220975119.7821
1995	3614940265.9522
1996	4072477921.948
1997	4731619237.19379
1998	4694628776.38866
1999	4836544732.16898
2000	4918236456.82793
2001	4950304905.37984
2002	5017258945.67723
2003	5374632307.34309
2004	5620489285.69088
2005	5873818474.31372
2006	6296402404.66891
2007	6646774782.09335
2008	6193682829.80932
2009	6481929511.41555
2010	6700440792.16592
2011	7015712096.28553
2012	7467734601.01982
2013	7831566172.69262
2014	9009844282.02552
2015	11037232242.8025
2016	11758913193.713
2017	12663211424.194