Quarter	Millions of US Dollars
2005-01-01	5907
2005-04-01	1724
2005-07-01	6238
2005-10-01	1006
2006-01-01	1170
2006-04-01	1725
2006-07-01	1248
2006-10-01	156
2007-01-01	8843
2007-04-01	-7627
2007-07-01	4308
2007-10-01	-2810
2008-01-01	7849
2008-04-01	-4452
2008-07-01	4270
2008-10-01	5501
2009-01-01	10397
2009-04-01	6111
2009-07-01	12806
2009-10-01	6303
2010-01-01	7156
2010-04-01	1692
2010-07-01	3470
2010-10-01	4263
2011-01-01	6510
2011-04-01	4736
2011-07-01	3226
2011-10-01	1740
2012-01-01	6284
2012-04-01	4552
2012-07-01	6282
2012-10-01	537
2013-01-01	5005
2013-04-01	2007
2013-07-01	6591
2013-10-01	-732
2014-01-01	3052
2014-04-01	675
2014-07-01	1873
2014-10-01	3532
2015-01-01	3020
2015-04-01	2600
2015-07-01	3201
2015-10-01	1205
2016-01-01	3865
2016-04-01	1422
2016-07-01	3257
2016-10-01	1703
2017-01-01	5000
2017-04-01	3474
2017-07-01	11192
2017-10-01	5488
2018-01-01	6247