Year	US Dollars
1990	9861724967.95507
1991	9378791836.24452
1992	8270129214.53557
1993	7137917944.93457
1994	5765546805.93733
1995	5520108764.03037
1996	6017575544.43208
1997	6624332333.62043
1998	6756531570.70681
1999	7027500686.00476
2000	7572329954.35719
2001	8340170944.6538
2002	8491017099.50822
2003	9304569732.80422
2004	10087951734.9635
2005	10504390403.9082
2006	11381188855.3601
2007	12725465379.0506
2008	13686607912.743
2009	14211371070.2029
2010	13945454348.3057
2011	14393401502.2784
2012	15968048603.3076
2013	17405395617.8618
2014	18754125551.5152
2015	19743545516.2001
2016	20568272791.3335
2017	22422002646.7055
