Year	US Dollars
1990	3120264750.37179
1991	3397323065.91313
1992	3202828029.60732
1993	3583231711.01593
1994	3889922633.20297
1995	4105475138.19954
1996	5396680287.6291
1997	6121776776.95935
1998	6877374564.2765
1999	7553504516.9517
2000	7733561722.72462
2001	8833343139.35011
2002	9014904154.39949
2003	10797263989.361
2004	11784844408.7854
2005	13186794654.373
2006	14465126879.8697
2007	16180361939.825
2008	17769810011.1768
2009	19656532498.5515
2010	21048562826.743
2011	23467220531.9072
2012	25867435172.06479
2013	28198802001.8737
2014	30586408011.0061
2015	32684878235.55211
2016	34220999935.2528
2017	35745142839.5825