Year	US Dollars, Monthly Level
1988-01-01	-2953759745.6411600
1989-01-01	-2466763488.7031800
1990-01-01	-3673801262.3282003
1991-01-01	-5587419743.2855010
1992-01-01	-6286064827.8924200
1993-01-01	-6404924745.7342100
1994-01-01	-7514648222.1579690
1995-01-01	-10310190322.8781990
1996-01-01	-10778321978.2892020
1997-01-01	-8373243908.7422905
1998-01-01	-6350346186.1746410
1999-01-01	-7864502882.7802900
2000-01-01	-6921814019.5878400
2001-01-01	-6973786130.0159610
2002-01-01	-6820167153.8498900
2003-01-01	-5768838943.8179210
2004-01-01	-6535802478.7133290
2005-01-01	-7948064478.5478900
2006-01-01	-7553285331.5088610
2007-01-01	-10148389736.0761000
2008-01-01	-13224966740.8357010
2009-01-01	-4878467759.3878700
2010-01-01	-7718021506.5365710
2011-01-01	-14891674333.7476000
2012-01-01	-17955384054.4143000
2013-01-01	-14114066747.6484000
2014-01-01	-14007564415.7757000
2015-01-01	-7899780822.2020200
2016-01-01	-12960766740.0189000
2017-01-01	-14974465325.6359000