Year	US Dollars
1990	24100232508.80061
1991	28164234770.094
1992	11420826460.907
1993	11847264760.1632
1994	9565804429.2079
1995	22095823307.3075
1996	22969134787.8869
1997	28473549380.1503
1998	29143044335.1032
1999	27602540706.7007
2000	30548627728.15299
2001	32935156925.3232
2002	40031765196.43351
2003	43137470671.069
2004	48582068984.5112
2005	59513803412.12489
2006	72559312017.4662
2007	94146665046.0428
2008	104602128019.14102
2009	117298693156.57903
2010	121803378448.67801
2011	129828008402.427
2012	139319739635.69498
2013	153292218132.88898
2014	165055684497.88303
2015	174116754095.02802
2016	175348960593.07001
2017	180460498541.22894