Quarter	Millions of US Dollars
1998-10-01	9
1999-01-01	11
1999-04-01	-5
1999-07-01	33
1999-10-01	4
2000-01-01	24
2000-04-01	2
2000-07-01	4
2000-10-01	-35
2001-01-01	-10
2001-04-01	14
2001-10-01	0
2002-01-01	9
2002-04-01	114
2002-07-01	14
2002-10-01	-5
2003-01-01	234
2003-04-01	10
2003-07-01	9
2003-10-01	6
2004-01-01	25
2004-04-01	123
2004-07-01	-34
2005-01-01	-56
2005-04-01	-42
2005-07-01	-12
2006-07-01	-268
2006-10-01	192
2007-07-01	421
2007-10-01	-304
2008-07-01	-45
2009-01-01	0
2009-10-01	376
2011-01-01	201
2012-04-01	393
2012-10-01	1219
2014-04-01	-548
2014-10-01	44
2015-04-01	32
2015-07-01	21
2015-10-01	543
2016-04-01	15
2016-07-01	24
2016-10-01	-193
2017-04-01	31
2017-07-01	-479
2017-10-01	-500