Year	US Dollars
1990	15614623120.0052
1991	17058190490.2678
1992	17952021981.8984
1993	19123893684.4715
1994	20533148851.1214
1995	21907102212.2345
1996	23538180462.2375
1997	25061777582.5619
1998	26762541097.4319
1999	27160657278.0212
2000	28382557402.5921
2001	29545785671.8507
2002	30746164953.8367
2003	31831387264.73899
2004	33840982165.5855
2005	36643646700.57159
2006	39775900832.762
2007	42582600608.8984
2008	46333351848.4522
2009	47918866662.4943
2010	50236861036.4764
2011	53690570040.49069
2012	56772683919.36369
2013	61474498230.2141
2014	66752479608.02221
2015	72044638300.8428
2016	77323948032.0318
2017	81058124055.4243