Quarter	Millions of US Dollars
2000-01-01	-2129
2000-04-01	2802
2000-07-01	-3934
2000-10-01	4851
2001-01-01	-4146
2001-04-01	-1547
2001-07-01	4827
2001-10-01	-1795
2002-01-01	-1467
2002-04-01	7420
2002-07-01	918
2002-10-01	3627
2003-01-01	171
2003-04-01	300
2003-07-01	2056
2003-10-01	3524
2004-01-01	-3545
2004-04-01	1286
2004-07-01	-1029
2004-10-01	7337
2005-01-01	-3975
2005-04-01	-4567
2005-07-01	-3594
2005-10-01	-430
2006-01-01	2032
2006-04-01	5779
2006-07-01	-2382
2006-10-01	837
2007-01-01	-1538
2007-04-01	-2027
2007-07-01	5019
2007-10-01	3740
2008-01-01	8726
2008-04-01	-1601
2008-07-01	-5258
2008-10-01	4066
2009-01-01	-7756
2009-04-01	4047
2009-07-01	5181
2009-10-01	577
2010-01-01	-2229
2010-04-01	191
2010-07-01	11506
2010-10-01	8714
2011-01-01	5474
2011-04-01	12753
2011-07-01	-5472
2011-10-01	-601
2012-01-01	7901
2012-04-01	-1642
2012-07-01	5119
2012-10-01	5626
2013-01-01	-1970
2013-04-01	2462
2013-07-01	7272
2013-10-01	6330
2014-01-01	3830
2014-04-01	2560
2014-07-01	-5073
2014-10-01	-2206
2015-01-01	6496
2015-04-01	11079
2015-07-01	-4698
2015-10-01	-756
2016-01-01	8012
2016-04-01	-1919
2016-07-01	3952
2016-10-01	-3862
2017-01-01	4112
2017-04-01	12306
2017-07-01	-2739
2017-10-01	797
2018-01-01	8388