Year	US Dollars, Monthly Level
1991-01-01	901728875.7343659
1992-01-01	-1181975434.3147900
1993-01-01	-86848212.4404994
1994-01-01	-1334839802.8516700
1995-01-01	-3799588768.3323197
1996-01-01	-5618388448.2616400
1997-01-01	-4692532780.5395900
1998-01-01	-2458183962.2199600
1999-01-01	-1774787762.8858300
2000-01-01	-3087849471.0271900
2001-01-01	-3123404350.9086404
2002-01-01	-2110237784.2463600
2003-01-01	-2505896537.3120500
2004-01-01	-858741489.4069481
2005-01-01	1684231215.0828800
2006-01-01	1757316306.9657900
2007-01-01	4343198224.4296200
2008-01-01	3861781728.1559800
2009-01-01	7818981553.3308000
2010-01-01	6508396817.2197500
2011-01-01	10699896925.0451010
2012-01-01	15542137149.9106000
2013-01-01	18074609726.6134000
2014-01-01	20679867535.5998000
2015-01-01	17651743856.6533000
2016-01-01	19175744784.5116000
2017-01-01	19256873240.3360980