Quarter	Millions of US Dollars
2000-01-01	-9256
2000-04-01	3690
2000-07-01	-9563
2000-10-01	8605
2001-01-01	-7183
2001-04-01	-5635
2001-07-01	13135
2001-10-01	-4486
2002-01-01	-1841
2002-04-01	19869
2002-07-01	225
2002-10-01	17414
2003-01-01	1355
2003-04-01	3711
2003-07-01	7932
2003-10-01	11924
2004-01-01	-2785
2004-04-01	5066
2004-07-01	3053
2004-10-01	20243
2005-01-01	-9594
2005-04-01	-15014
2005-07-01	-3898
2005-10-01	-2167
2006-01-01	6881
2006-04-01	8929
2006-07-01	-5518
2006-10-01	3111
2007-01-01	-2002
2007-04-01	-6822
2007-07-01	12215
2007-10-01	9845
2008-01-01	23168
2008-04-01	-6418
2008-07-01	-16993
2008-10-01	11578
2009-01-01	-23032
2009-04-01	13193
2009-07-01	16254
2009-10-01	-3390
2010-01-01	-2704
2010-04-01	3255
2010-07-01	18274
2010-10-01	18723
2011-01-01	10726
2011-04-01	25450
2011-07-01	-16677
2011-10-01	-4227
2012-01-01	24800
2012-04-01	-17933
2012-07-01	9975
2012-10-01	14688
2013-01-01	-10296
2013-04-01	6306
2013-07-01	18222
2013-10-01	8201
2014-01-01	7119
2014-04-01	3415
2014-07-01	-13884
2014-10-01	-8364
2015-01-01	16107
2015-04-01	15124
2015-07-01	-14967
2015-10-01	-774
2016-01-01	11712
2016-04-01	-6936
2016-07-01	6282
2016-10-01	-13308
2017-01-01	9885
2017-04-01	16993
2017-07-01	-3793
2017-10-01	3006
2018-01-01	8410