Year	US Dollars
1990	138543083185.19803
1991	148203412981.55597
1992	153115849681.80301
1993	153750190305.57401
1994	160219332962.21396
1995	167038102549.216
1996	173690858375.29803
1997	184532986309.75201
1998	194084315334.13998
1999	196470733424.43005
2000	212328865743.88605
2001	229640432365.89798
2002	246506012516.45996
2003	260092925667.164
2004	275501040440.46802
2005	281471978035.92804
2006	308503000934.95197
2007	315238637893.24994
2008	331637075588.56494
2009	329722796253.34003
2010	306934275526.76898
2011	282370859957.68103
2012	281120340956.06207
2013	285824079577.24396
2014	294315512120.88995
2015	290196597811.28699
2016	289947135091.99799
2017	297160492216.65796