Year	US Dollars, Monthly Level
1991-01-01	7875389908.776120
1992-01-01	8756152078.946220
1993-01-01	14392520673.148900
1994-01-01	15977928072.308300
1995-01-01	21368427547.321400
1996-01-01	22168289818.091000
1997-01-01	22281241317.321900
1998-01-01	25866635883.126800
1999-01-01	26015703193.749702
2000-01-01	29121711389.237300
2001-01-01	33421585104.353300
2002-01-01	38526084464.164400
2003-01-01	48643793686.973800
2004-01-01	67023159712.276695
2005-01-01	77846090830.689000
2006-01-01	95452723624.755300
2007-01-01	123044406135.867000
2008-01-01	146140986557.214020
2009-01-01	113533169968.349000
2010-01-01	132831361731.452010
2011-01-01	162780365899.272980
2012-01-01	157683399581.772000
2013-01-01	162585086010.158000
2014-01-01	175079508511.976000
2015-01-01	158511559081.121000
2016-01-01	162466494710.435000
2017-01-01	182497946053.791000