Quarter	Millions of US Dollars
2004-04-01	229
2004-07-01	16
2004-10-01	4
2005-01-01	-34
2005-04-01	524
2005-07-01	438
2005-10-01	1132
2006-01-01	971
2006-04-01	605
2006-07-01	1682
2006-10-01	2092
2007-01-01	1611
2007-04-01	2267
2007-07-01	249
2007-10-01	3326
2008-01-01	2039
2008-04-01	3049
2008-07-01	1868
2008-10-01	1378
2009-01-01	106
2009-04-01	950
2009-07-01	1360
2009-10-01	2146
2010-01-01	461
2010-04-01	591
2010-07-01	3097
2010-10-01	3614
2011-01-01	1264
2011-04-01	2140
2011-07-01	1347
2011-10-01	3644
2012-01-01	5344
2012-04-01	1685
2012-07-01	4725
2012-10-01	6689
2013-01-01	3498
2013-04-01	2170
2013-07-01	4916
2013-10-01	6548
2014-01-01	3621
2014-04-01	9077
2014-07-01	1946
2014-10-01	4608
2015-01-01	394
2015-04-01	2395
2015-07-01	1606
2015-10-01	994
2016-01-01	-304
2016-04-01	4158
2016-07-01	-1581
2016-10-01	101
2017-01-01	2896
2017-04-01	5045
2017-07-01	385
2017-10-01	2705
2018-01-01	1103