Quarter	Millions of US Dollars
1997-01-01	4871
1998-10-01	-740
2002-01-01	740
2002-04-01	-18
2002-10-01	-418
2003-01-01	732
2003-07-01	-36
2003-10-01	-410
2004-04-01	500
2004-10-01	806
2005-01-01	333
2005-07-01	750
2005-10-01	500
2006-01-01	-100
2007-01-01	1417
2007-04-01	-102
2007-07-01	521
2008-01-01	-1442
2009-01-01	1000
2009-07-01	1000
2010-04-01	573
2010-10-01	2506
2012-01-01	1087
2014-10-01	2940
2015-01-01	823
2015-07-01	1250
2015-10-01	1214
2016-01-01	1107
2016-04-01	-1223
2016-10-01	1634
2017-01-01	0