Quarter	Millions of US Dollars
2005-04-01	3506
2005-07-01	354
2005-10-01	2242
2006-01-01	3795
2006-04-01	1547
2006-07-01	2551
2006-10-01	8870
2007-01-01	10971
2007-04-01	5787
2007-07-01	3120
2007-10-01	11936
2008-01-01	5075
2008-04-01	5203
2008-07-01	-4849
2008-10-01	-2104
2009-01-01	3918
2009-04-01	1373
2009-07-01	3006
2009-10-01	6862
2010-01-01	6483
2010-04-01	3239
2010-07-01	9275
2010-10-01	5372
2011-01-01	8744
2011-04-01	4765
2011-07-01	7606
2011-10-01	4505
2012-01-01	2145
2012-04-01	-10804
2012-07-01	-9807
2012-10-01	6677
2013-01-01	11724
2013-04-01	-12027
2013-07-01	-9109
2013-10-01	-1511
2014-01-01	589
2014-04-01	2793
2014-07-01	-3029
2014-10-01	2884
2015-01-01	-5017
2015-04-01	4163
2015-07-01	-3789
2015-10-01	-1668
2016-01-01	17686
2016-04-01	-4536
2016-07-01	-3583
2016-10-01	4167
2017-01-01	3914
2017-04-01	-4681
2017-07-01	-3741
2017-10-01	4877
2018-01-01	-2049