Year	US Dollars, Monthly Level
1991-01-01	15081422770.614600
1992-01-01	15959619638.956000
1993-01-01	18723900813.003100
1994-01-01	21423720705.521200
1995-01-01	29248493502.086800
1996-01-01	37164088935.234200
1997-01-01	42423167408.005196
1998-01-01	46803891826.513100
1999-01-01	45910892432.586400
2000-01-01	49467481281.601105
2001-01-01	50692106964.396996
2002-01-01	55357467191.502900
2003-01-01	68578556783.670510
2004-01-01	89598106460.465800
2005-01-01	102316321701.819000
2006-01-01	128307725484.040990
2007-01-01	167171943552.857000
2008-01-01	210231093828.597020
2009-01-01	150541306362.712000
2010-01-01	177866939342.219020
2011-01-01	211211550232.001980
2012-01-01	199622933243.468000
2013-01-01	207478671006.712000
2014-01-01	223427367394.930000
2015-01-01	196329304656.054020
2016-01-01	199685276703.641000
2017-01-01	233864326367.571000