Quarter	Millions of US Dollars
2002-01-01	838
2002-04-01	-3053
2002-07-01	7202
2002-10-01	-555
2003-01-01	5706
2003-04-01	-189
2003-07-01	1230
2003-10-01	5672
2004-01-01	2696
2004-04-01	-1967
2004-07-01	3196
2004-10-01	1364
2005-01-01	74
2005-04-01	-5302
2005-07-01	848
2005-10-01	8732
2006-01-01	-6064
2006-04-01	-764
2006-07-01	-2751
2006-10-01	5419
2007-01-01	-5019
2007-04-01	-6294
2007-07-01	-12012
2007-10-01	4289
2008-01-01	-5360
2008-04-01	-11900
2008-07-01	10850
2008-10-01	-2898
2009-01-01	-5894
2009-04-01	-279
2009-07-01	-959
2009-10-01	2722
2010-01-01	3793
2010-04-01	419
2010-07-01	-4460
2010-10-01	6000
2011-01-01	-5669
2011-04-01	3074
2011-07-01	-4375
2011-10-01	3546
2012-01-01	-286
2012-04-01	2552
2012-07-01	-228
2012-10-01	-2397
2013-01-01	6098
2013-04-01	1871
2013-07-01	-1627
2013-10-01	4591
2014-01-01	3085
2014-04-01	-3258
2014-07-01	478
2014-10-01	1146
2015-01-01	4489
2015-04-01	7345
2015-07-01	-7538
2015-10-01	1945
2016-01-01	-1072
2016-04-01	5478
2016-07-01	-8161
2016-10-01	1586
2017-01-01	754
2017-04-01	569
2017-07-01	-7192
2017-10-01	3066
2018-01-01	-4244