Quarter	Millions of US Dollars
2002-07-01	-4047
2002-10-01	2671
2003-01-01	-7699
2003-04-01	-2359
2003-07-01	-18290
2003-10-01	2471
2004-01-01	-10504
2004-04-01	-4559
2004-07-01	-7611
2004-10-01	-1508
2005-01-01	-4564
2005-04-01	3194
2005-07-01	570
2005-10-01	-8822
2006-01-01	-9594
2006-04-01	-2507
2006-07-01	-3697
2006-10-01	174
2007-01-01	2632
2007-04-01	352
2007-07-01	-1124
2007-10-01	-323
2008-01-01	11152
2008-04-01	722
2008-07-01	4023
2008-10-01	12204
2009-01-01	27618
2009-04-01	20899
2009-07-01	17057
2009-10-01	11552
2010-01-01	14535
2010-04-01	16967
2010-07-01	16505
2010-10-01	11030
2011-01-01	13359
2011-04-01	11504
2011-07-01	11139
2011-10-01	11877
2012-01-01	13264
2012-04-01	14708
2012-07-01	22635
2012-10-01	12990
2013-01-01	13407
2013-04-01	11312
2013-07-01	8261
2013-10-01	12068
2014-01-01	-3243
2014-04-01	2118
2014-07-01	1324
2014-10-01	-35173
2015-01-01	-55
2015-04-01	27379
2015-07-01	3681
2015-10-01	-3259
2016-01-01	102
2016-04-01	864
2016-07-01	-80
2016-10-01	-692
2017-01-01	678
2017-04-01	10558
2017-07-01	-1264
2017-10-01	-966
2018-01-01	1970