Year	US Dollars, Monthly Level
1990-01-01	4017831378.9065003
1991-01-01	3126531250.6665200
1992-01-01	6789266181.2930700
1993-01-01	8651618070.0259800
1994-01-01	7817155485.0141390
1995-01-01	4906545069.6726290
1996-01-01	6739161877.3974900
1997-01-01	12541574890.0826000
1998-01-01	21256264510.3155000
1999-01-01	24314138187.3854980
2000-01-01	28857293072.4410970
2001-01-01	25175749961.7438000
2002-01-01	26299363983.5431980
2003-01-01	27930692343.4825020
2004-01-01	25161066902.7946000
2005-01-01	28297899095.0452000
2006-01-01	39737497780.2464000
2007-01-01	39132388527.0702000
2008-01-01	12552972367.4854010
2009-01-01	17607864405.1852000
2010-01-01	22192183657.2170000
2011-01-01	25833982223.6725000
2012-01-01	-867232202.7480091
2013-01-01	-4358933004.7869700
2014-01-01	-891551889.2007540
2015-01-01	7050141226.9134300
2016-01-01	9701391957.6347300
2017-01-01	11367715436.6429000