Year	US Dollars
1990	7872957481.17318
1991	6458093738.63595
1992	6165361427.63148
1993	6552770212.35927
1994	8043416728.95148
1995	9026638747.15843
1996	9927149464.35246
1997	10667574117.9056
1998	11425425923.1216
1999	12409305782.5769
2000	13226256732.3139
2001	13846552486.7898
2002	14250112397.3367
2003	14934361743.593
2004	16228862949.5948
2005	17638531251.9452
2006	18713829660.132
2007	20303026575.0086
2008	21962659103.383
2009	21397164679.4252
2010	22617803144.587
2011	24545188250.1326
2012	26620566544.47949
2013	28385076983.918
2014	30282925737.4191
2015	32419359883.6522
2016	34114464538.0154
2017	35298158639.02369