Quarter	Millions of US Dollars
1995-04-01	0
1995-07-01	0
1995-10-01	0
1996-01-01	10399
1996-04-01	0
1996-07-01	0
1996-10-01	0
1997-01-01	11732
1997-04-01	0
1997-07-01	0
1997-10-01	0
1998-01-01	13332
1998-04-01	0
1998-07-01	0
1998-10-01	0
1999-01-01	33331
1999-04-01	0
1999-07-01	0
1999-10-01	0
2000-01-01	7199
2000-04-01	0
2000-07-01	0
2000-10-01	0
2001-01-01	-16798
2001-04-01	0
2001-07-01	0
2001-10-01	0
2002-01-01	31465
2002-04-01	0
2002-07-01	0
2002-10-01	0
2003-01-01	11466
2003-04-01	0
2003-07-01	0
2003-10-01	0
2004-01-01	-8533
2004-04-01	0
2004-07-01	0
2004-10-01	0
2005-01-01	-46930
2005-04-01	0
2005-07-01	0
2005-10-01	0
2006-01-01	-18663
2006-04-01	0
2006-07-01	0
2006-10-01	0
2007-01-01	-25865
2007-04-01	0
2007-07-01	0
2007-10-01	0
2008-01-01	-7997
2008-04-01	0
2008-07-01	0
2008-10-01	0
2009-01-01	-3200
2009-04-01	0
2009-07-01	0
2009-10-01	0
2010-01-01	-15466
2010-04-01	0
2010-07-01	0
2010-10-01	0
2011-01-01	-8400
2011-04-01	0
2011-07-01	0
2011-10-01	0
2012-01-01	-13786
2012-04-01	0
2012-07-01	0
2012-10-01	0
2013-01-01	-1200
2013-04-01	-2480
2013-07-01	-1627
2013-10-01	-1013
2014-01-01	-1387
2014-04-01	-320
2014-07-01	-906
2014-10-01	-1598
2015-01-01	-1333
2015-04-01	560
2015-07-01	9999
2015-10-01	16881
2016-01-01	10692
2016-04-01	10373
2016-07-01	3782
2016-10-01	-5864
2017-01-01	-2346
2017-04-01	-50
2017-07-01	9171
2017-10-01	5493
2018-01-01	4776