Year	US Dollars
1990	4231452772.82761
1991	4788257318.01516
1992	5304316461.53376
1993	4445403708.99579
1994	5106672776.25982
1995	5294165211.59379
1996	5494754677.74487
1997	5878692634.3157
1998	6422069780.90682
1999	6471486276.22705
2000	6484647094.04988
2001	7401380643.52858
2002	8013673179.61879
2003	8051683738.02709
2004	11185649196.7199
2005	13597538457.3716
2006	13955954817.7679
2007	15228498755.5574
2008	15594877414.7634
2009	18695711630.0695
2010	21674629067.5024
2011	22309202431.6998
2012	24782590694.6897
2013	26034201097.9971
2014	28398389195.6568
2015	29905962189.445
2016	28698625186.26
2017	28545163090.2455