Year	US Dollars
1990	41666030633.68831
1991	38465838632.31791
1992	39937651392.38749
1993	40225615324.17711
1994	41741075794.58849
1995	43239738167.21949
1996	45185313212.85011
1997	45756288579.7224
1998	48648900469.96281
1999	46576844230.59429
2000	50818986096.5993
2001	55478694869.7403
2002	61830969500.58301
2003	65929024164.53661
2004	71253432852.46761
2005	78428536066.39308
2006	83861008050.883
2007	89534128787.36861
2008	102780040612.64799
2009	103319251865.31699
2010	108251715721.05602
2011	111574754974.58199
2012	116829118878.31201
2013	118170674215.192
2014	125386660245.078
2015	127417753902.452
2016	136800995904.53099
2017	145081198987.53198