Quarter	Millions of US Dollars
1981-10-01	25
1986-10-01	-25
1994-01-01	71
1994-04-01	40
1994-10-01	25
1995-01-01	0
1995-04-01	-25
1995-10-01	17
1996-01-01	-8
1996-04-01	-15
1996-07-01	-8
1997-01-01	4848
1997-04-01	25
1998-01-01	-11
1998-04-01	15
1998-07-01	-4
1998-10-01	-590
1999-01-01	-25
1999-04-01	-10
1999-07-01	-10
1999-10-01	-1
2000-10-01	-3
2002-01-01	740
2002-04-01	-68
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	780
2006-01-01	100
2006-07-01	213
2006-10-01	754
2007-01-01	1417
2007-04-01	192
2007-07-01	1025
2007-10-01	177
2008-01-01	-1439
2008-04-01	3
2008-07-01	153
2008-10-01	-147
2009-01-01	1003
2009-04-01	3
2009-07-01	1043
2009-10-01	575
2010-01-01	329
2010-04-01	971
2010-07-01	819
2010-10-01	3034
2011-01-01	789
2011-04-01	4
2011-07-01	654
2011-10-01	624
2012-01-01	3216
2012-04-01	1881
2012-07-01	920
2012-10-01	11
2013-01-01	1874
2013-04-01	1911
2013-07-01	-9
2013-10-01	676
2014-01-01	1306
2014-04-01	662
2014-07-01	1477
2014-10-01	4024
2015-01-01	1233
2015-04-01	761
2015-07-01	2056
2015-10-01	1226
2016-01-01	213
2016-04-01	-1216
2016-07-01	-234
2016-10-01	1941
2017-01-01	-588
2017-04-01	3556
2017-07-01	-393
2017-10-01	625
2018-01-01	-771
2018-04-01	-371