Year	US Dollars
1990	3756324418.09537
1991	4089833755.53602
1992	4212605599.65925
1993	4052539721.95757
1994	3972859161.88532
1995	3734101527.95753
1996	3485338149.8039
1997	3499814254.50192
1998	3719212556.34057
1999	3720245424.16367
2000	3888667428.25641
2001	3937347267.87095
2002	4164829639.11602
2003	4169325526.95847
2004	4458775641.68245
2005	4710608601.80232
2006	5163205368.46635
2007	5568617974.62618
2008	5974557597.68447
2009	6184364739.19749
2010	6521832895.49804
2011	6925318798.35938
2012	7364005758.91345
2013	7860854608.61092
2014	8351046010.98508
2015	8123987508.50647
2016	8182899808.34421
2017	8366312305.32082