Year	US Dollars
1990	24298612847.8723
1991	25516622712.7702
1992	28817740217.3508
1993	31133892003.9498
1994	32774136205.4128
1995	35215273779.0163
1996	38610323876.8548
1997	42081082504.4874
1998	45235907754.1134
1999	48699117198.9286
2000	52563770020.6628
2001	54226881163.5915
2002	57487151505.43079
2003	57204343332.3894
2004	58486489923.38891
2005	65872508675.7737
2006	74618807173.59679
2007	87429916162.0385
2008	93284479378.34792
2009	94944245326.601
2010	103990318908.028
2011	109083978280.96399
2012	114091494443.44
2013	119273840901.548
2014	130235954438.23402
2015	142051193571.61801
2016	152755011352.35699
2017	164661198448.17899