Year	US Dollars
1990	10364794228.4519
1991	10111198155.223
1992	9420612192.49063
1993	9005871835.35014
1994	9113893449.7614
1995	9245871113.87324
1996	9499991786.11161
1997	9772563694.4142
1998	10233758377.6227
1999	10762096574.6299
2000	12234176866.7566
2001	12235720415.6441
2002	12772192086.3782
2003	13189989111.9763
2004	14478819636.7517
2005	15708296565.8556
2006	17643052727.2969
2007	18196216847.7213
2008	21276989149.761
2009	22417958704.3108
2010	23042274959.503
2011	23634779001.7868
2012	24026859294.4468
2013	25647227310.5356
2014	27256168402.1148
2015	27720474712.8358
2016	29448478972.77069
2017	30392969926.9487