Quarter	Millions of US Dollars
2002-07-01	3031
2002-10-01	3495
2003-01-01	1491
2003-04-01	6256
2003-07-01	11496
2003-10-01	12973
2004-01-01	15086
2004-04-01	5305
2004-07-01	10293
2004-10-01	7563
2005-01-01	16207
2005-04-01	12935
2005-07-01	4394
2005-10-01	9649
2006-01-01	14197
2006-04-01	20683
2006-07-01	3839
2006-10-01	4948
2007-01-01	8235
2007-04-01	9103
2007-07-01	-483
2007-10-01	1494
2008-01-01	7855
2008-04-01	8425
2008-07-01	-9741
2008-10-01	5656
2009-01-01	11731
2009-04-01	7167
2009-07-01	19347
2009-10-01	-535
2010-01-01	22919
2010-04-01	1384
2010-07-01	12520
2010-10-01	-5531
2011-01-01	18376
2011-04-01	9641
2011-07-01	1693
2011-10-01	2189
2012-01-01	15976
2012-04-01	7963
2012-07-01	2284
2012-10-01	-2339
2013-01-01	19557
2013-04-01	14348
2013-07-01	2634
2013-10-01	3081
2014-01-01	21953
2014-04-01	20923
2014-07-01	-2052
2014-10-01	1483
2015-01-01	27951
2015-04-01	13703
2015-07-01	7885
2015-10-01	2562
2016-01-01	22595
2016-04-01	13745
2016-07-01	151
2016-10-01	-2911
2017-01-01	22813
2017-04-01	11781
2017-07-01	247
2017-10-01	-489
2018-01-01	24589