Year	US Dollars
1990	11008775425.9943
1991	12450207108.3228
1992	12897451124.653
1993	13499136864.9825
1994	13788849085.7942
1995	15364574415.4487
1996	16113992712.1931
1997	17354620834.2273
1998	17754727470.7081
1999	19959366352.349
2000	21453417717.01649
2001	22284982414.5795
2002	22231998148.3726
2003	22170286307.1012
2004	26951746231.8818
2005	29385801220.0392
2006	30076235390.0279
2007	34983861337.1954
2008	35086723108.289
2009	27811779083.0825
2010	31421501258.0949
2011	33200445476.1302
2012	33825637688.9908
2013	34690043272.6355
2014	36591346599.73901
2015	38715487338.119
2016	40528972635.082
2017	43576800962.871