Year	US Dollars, Monthly Level
1991-01-01	-10780925556.70310
1992-01-01	-9927833002.00559
1993-01-01	10854190013.57430
1994-01-01	16651326814.45210
1995-01-01	20367805320.52530
1996-01-01	19197274866.50940
1997-01-01	14169356953.33270
1998-01-01	15380159329.33700
1999-01-01	31893486347.64000
2000-01-01	57512136014.36560
2001-01-01	45963607306.61470
2002-01-01	43503534173.56860
2003-01-01	55972993904.25580
2004-01-01	83418065047.44890
2005-01-01	116362654340.30101
2006-01-01	135921277604.71999
2007-01-01	123584504639.82700
2008-01-01	177081329106.11700
2009-01-01	112822832916.44600
2010-01-01	150188498708.98700
2011-01-01	197755625069.98900
2012-01-01	193387896565.58900
2013-01-01	180328449222.70700
2014-01-01	188526712416.27000
2015-01-01	149465194074.20602
2016-01-01	90783579174.89990
2017-01-01	116025989354.46700