Year	US Dollars
1990	22528581651.2232
1991	23918955866.1187
1992	24524154776.6484
1993	25466536669.674
1994	26538386941.9712
1995	28333834309.3321
1996	30581436016.8993
1997	32047074784.0948
1998	33752656422.43909
1999	35980226815.1377
2000	38498490716.6264
2001	40971431615.8953
2002	45586605110.2771
2003	49312773644.6522
2004	54566714576.6942
2005	60736805195.26589
2006	66841476733.0134
2007	73542785112.82178
2008	79291471165.4576
2009	84283627212.16458
2010	90729900568.3497
2011	100210752121.416
2012	106532246489.666
2013	116766008359.41302
2014	126948909446.08798
2015	136449844723.54097
2016	148794881399.01697
2017	162247376575.78198