Year	US Dollars
1990	28470717205.8808
1991	23487928619.10609
1992	24446638239.09389
1993	22394359384.2311
1994	20598432833.89989
1995	20762464274.8759
1996	22645793311.36769
1997	21692423171.895
1998	21658915350.4265
1999	20414680535.0704
2000	20952319389.942
2001	20331721327.3669
2002	21621529330.052
2003	23493665970.1395
2004	25645577452.0194
2005	27733062279.6686
2006	30417803795.0019
2007	32997082553.01939
2008	34650133857.29401
2009	36875084154.8052
2010	39974566039.38319
2011	43243275549.00541
2012	46947732390.49949
2013	50025251400.45969
2014	55828711983.5797
2015	61065792437.6679
2016	66907175960.33989
2017	70728832167.2132