Year	US Dollars
1990	9425728378.05048
1991	13470863127.0214
1992	14209792452.4569
1993	15704222080.9216
1994	15894677831.4801
1995	17452312543.606
1996	18612559212.2022
1997	18868824747.7327
1998	20216563698.5331
1999	21084470713.0799
2000	23090979986.5766
2001	23928992957.26
2002	24686622654.21169
2003	26977485405.2054
2004	29679108024.6221
2005	33317998126.33809
2006	36751739070.3886
2007	41155217221.6339
2008	43580471538.5892
2009	41818457042.95329
2010	44771842447.26329
2011	45304049174.4875
2012	47470308994.02231
2013	51090175533.27891
2014	51245353865.5157
2015	60590568956.38078
2016	62718667760.54911
2017	64070909509.8382