Year	US Dollars
1990	26849966214.2205
1991	27880366972.0919
1992	31136656490.2645
1993	34207960783.1936
1994	36307973125.8221
1995	39477223210.1301
1996	43772396275.378
1997	49743240998.5282
1998	52279483926.5013
1999	54152990512.54829
2000	57976350122.42509
2001	62523419248.94209
2002	67804064414.8199
2003	73278226068.2677
2004	78342845304.35789
2005	87349015706.53819
2006	100357089888.17999
2007	113903337593.345
2008	125437532280.64999
2009	129475487031.26501
2010	135153486301.04599
2011	140669381805.509
2012	137587245482.25
2013	99332603179.30881
2014	150417010612.43005
2015	160549534107.79599
2016	169626879888.496
2017	181665035763.69891