Quarter	Millions of US Dollars
2005-01-01	5907
2005-04-01	1724
2005-07-01	6238
2005-10-01	996
2006-01-01	1170
2006-04-01	1725
2006-07-01	1182
2006-10-01	142
2007-01-01	8843
2007-04-01	-7617
2007-07-01	3763
2007-10-01	-3311
2008-01-01	8540
2008-04-01	-4469
2008-07-01	4230
2008-10-01	5482
2009-01-01	10472
2009-04-01	6127
2009-07-01	12770
2009-10-01	6268
2010-01-01	7014
2010-04-01	1558
2010-07-01	3182
2010-10-01	3281
2011-01-01	4569
2011-04-01	1739
2011-07-01	2135
2011-10-01	1103
2012-01-01	3600
2012-04-01	1394
2012-07-01	5550
2012-10-01	-635
2013-01-01	3460
2013-04-01	1563
2013-07-01	5950
2013-10-01	-2301
2014-01-01	2782
2014-04-01	-274
2014-07-01	-90
2014-10-01	2759
2015-01-01	3265
2015-04-01	2634
2015-07-01	2623
2015-10-01	668
2016-01-01	2874
2016-04-01	1744
2016-07-01	3261
2016-10-01	1582
2017-01-01	4042
2017-04-01	3407
2017-07-01	7919
2017-10-01	3149
2018-01-01	3768