Quarter	Millions of US Dollars
2000-04-01	6704
2000-07-01	4175
2000-10-01	15393
2001-01-01	2561
2001-04-01	6078
2001-07-01	5523
2001-10-01	7791
2002-01-01	23968
2002-04-01	19336
2002-07-01	12919
2002-10-01	8458
2003-01-01	4229
2003-04-01	16794
2003-07-01	5060
2003-10-01	30795
2004-01-01	3402
2004-04-01	12673
2004-07-01	18934
2004-10-01	2950
2005-01-01	-506
2005-04-01	5707
2005-07-01	13986
2005-10-01	16550
2006-01-01	-2899
2006-04-01	-3274
2006-07-01	14323
2006-10-01	17115
2007-01-01	1205
2007-04-01	11792
2007-07-01	99016
2007-10-01	123647
2008-01-01	-101
2008-04-01	14659
2008-07-01	4209
2008-10-01	14140
2009-01-01	3626
2009-04-01	65127
2009-07-01	45429
2009-10-01	12604
2010-01-01	-3529
2010-04-01	51831
2010-07-01	49294
2010-10-01	40055
2011-01-01	645
2011-04-01	42686
2011-07-01	52229
2011-10-01	48655
2012-01-01	5130
2012-04-01	10464
2012-07-01	67211
2012-10-01	23722
2013-01-01	27991
2013-04-01	62402
2013-07-01	73681
2013-10-01	47407
2014-01-01	-4962
2014-04-01	41897
2014-07-01	104070
2014-10-01	50332
2015-01-01	-26556
2015-04-01	189838
2015-07-01	312859
2015-10-01	265832
2016-01-01	133736
2016-04-01	467585
2016-07-01	293643
2016-10-01	171654
2017-01-01	53784
2017-04-01	280414
2017-07-01	291315
2017-10-01	210621
2018-01-01	31732