Quarter	Millions of US Dollars
2005-04-01	6606
2005-07-01	1105
2005-10-01	-716
2006-01-01	4427
2006-04-01	1569
2006-07-01	3258
2006-10-01	2028
2007-01-01	5489
2007-04-01	2590
2007-07-01	-4050
2007-10-01	1322
2008-01-01	6010
2008-04-01	4831
2008-07-01	-3851
2008-10-01	-8070
2009-01-01	-2478
2009-04-01	1299
2009-07-01	-5676
2009-10-01	-2570
2010-01-01	-1884
2010-04-01	11571
2010-07-01	2611
2010-10-01	3132
2011-01-01	4245
2011-04-01	3773
2011-07-01	8228
2011-10-01	-7065
2012-01-01	7687
2012-04-01	-1350
2012-07-01	2814
2012-10-01	-2355
2013-01-01	-5067
2013-04-01	-3399
2013-07-01	-1047
2013-10-01	207
2014-01-01	-2057
2014-04-01	-1007
2014-07-01	11176
2014-10-01	7864
2015-01-01	-10727
2015-04-01	-11633
2015-07-01	-2144
2015-10-01	3133
2016-01-01	-3079
2016-04-01	-3670
2016-07-01	-1724
2016-10-01	444
2017-01-01	-273
2017-04-01	-136
2017-07-01	-887
2017-10-01	1574
2018-01-01	138