Quarter	Millions of US Dollars
2004-04-01	356
2004-07-01	274
2004-10-01	1792
2005-01-01	439
2005-04-01	1760
2005-07-01	863
2005-10-01	2442
2006-01-01	2365
2006-04-01	1175
2006-07-01	2384
2006-10-01	4402
2007-01-01	1673
2007-04-01	3729
2007-07-01	2183
2007-10-01	-661
2008-01-01	7721
2008-04-01	2522
2008-07-01	2454
2008-10-01	1061
2009-01-01	-232
2009-04-01	4926
2009-07-01	7173
2009-10-01	6487
2010-01-01	1375
2010-04-01	-444
2010-07-01	3479
2010-10-01	1924
2011-01-01	5363
2011-04-01	4774
2011-07-01	-1961
2011-10-01	851
2012-01-01	1609
2012-04-01	-328
2012-07-01	-1557
2012-10-01	4390
2013-01-01	5401
2013-04-01	3032
2013-07-01	-55
2013-10-01	5395
2014-01-01	-2454
2014-04-01	-800
2014-07-01	-1265
2014-10-01	11480
2015-01-01	6927
2015-04-01	2622
2015-07-01	2037
2015-10-01	1407
2016-01-01	-171
2016-04-01	4091
2016-07-01	1905
2016-10-01	13061
2017-01-01	1838
2017-04-01	4228
2017-07-01	5635
2017-10-01	12741
2018-01-01	2285