Quarter	Millions of US Dollars
2007-01-01	589
2007-04-01	-91
2007-07-01	-219
2007-10-01	633
2008-01-01	18
2008-04-01	-332
2008-07-01	-230
2008-10-01	986
2009-01-01	67
2009-04-01	-38
2009-07-01	263
2009-10-01	427
2010-01-01	849
2010-04-01	122
2010-07-01	992
2010-10-01	150
2011-01-01	359
2011-04-01	-449
2011-07-01	570
2011-10-01	393
2012-01-01	1010
2012-04-01	-543
2012-07-01	406
2012-10-01	287
2013-01-01	582
2013-04-01	-78
2013-07-01	478
2013-10-01	281
2014-01-01	757
2014-04-01	40
2014-07-01	-59
2014-10-01	731
2015-01-01	128
2015-04-01	-92
2015-07-01	181
2015-10-01	41
2016-01-01	566
2016-04-01	-204
2016-07-01	807
2016-10-01	110
2017-01-01	359
2017-04-01	139
2017-07-01	462
2017-10-01	110
2018-01-01	255