Quarter	Millions of US Dollars
1996-01-01	1983
1996-04-01	-1146
1996-07-01	1962
1996-10-01	-435
1997-01-01	2510
1997-04-01	1057
1997-07-01	41
1997-10-01	854
1998-01-01	1647
1998-04-01	-357
1998-07-01	938
1998-10-01	206
1999-01-01	1137
1999-04-01	-3521
1999-07-01	653
1999-10-01	402
2000-01-01	-714
2000-04-01	-1307
2000-07-01	832
2000-10-01	946
2001-01-01	2002
2001-04-01	-106
2001-07-01	845
2001-10-01	-925
2002-01-01	1370
2002-04-01	821
2002-07-01	1632
2002-10-01	298
2003-01-01	29
2003-04-01	-420
2003-07-01	-724
2003-10-01	1661
2004-01-01	-485
2004-04-01	1293
2004-07-01	897
2004-10-01	1969
2005-01-01	736
2005-04-01	-1217
2005-07-01	3700
2005-10-01	-338
2006-01-01	1176
2006-04-01	-2220
2006-07-01	2070
2006-10-01	3880
2007-01-01	-4294
2007-04-01	-529
2007-07-01	5338
2007-10-01	2982
2008-01-01	-845
2008-04-01	2911
2008-07-01	1870
2008-10-01	9169
2009-01-01	8339
2009-04-01	12512
2009-07-01	11735
2009-10-01	1488
2010-01-01	-465
2010-04-01	1378
2010-07-01	3590
2010-10-01	1184
2011-01-01	1566
2011-04-01	3463
2011-07-01	4251
2011-10-01	7362
2012-01-01	1487
2012-04-01	1960
2012-07-01	3461
2012-10-01	1330
2013-01-01	2897
2013-04-01	255
2013-07-01	332
2013-10-01	-1718
2014-01-01	3836
2014-04-01	-6275
2014-07-01	-2138
2014-10-01	-500
2015-01-01	-1968
2015-04-01	-288
2015-07-01	1508
2015-10-01	-902
2016-01-01	2921
2016-04-01	-536
2016-07-01	2295
2016-10-01	2078
2017-01-01	3458
2017-04-01	1168
2017-07-01	392
2017-10-01	-1152
2018-01-01	2375