Quarter	Millions of US Dollars
1996-10-01	200
1997-10-01	350
1998-04-01	100
1999-10-01	100
2000-04-01	350
2001-04-01	0
2001-07-01	150
2002-01-01	109
2002-04-01	250
2002-10-01	-200
2003-01-01	0
2003-04-01	825
2004-01-01	500
2004-04-01	500
2004-10-01	1975
2005-01-01	700
2005-04-01	400
2005-07-01	300
2005-10-01	1950
2006-01-01	1756
2006-04-01	2700
2006-07-01	2960
2006-10-01	2641
2007-01-01	5184
2007-04-01	3312
2007-07-01	445
2007-10-01	980
2008-01-01	-158
2008-04-01	693
2008-07-01	3972
2008-10-01	-350
2009-01-01	-862
2009-04-01	-100
2009-07-01	1435
2009-10-01	21
2010-01-01	863
2010-04-01	580
2010-07-01	-1050
2010-10-01	4950
2011-01-01	-136
2011-04-01	-645
2011-07-01	-1887
2011-10-01	-629
2012-01-01	-1955
2012-04-01	277
2012-07-01	1616
2012-10-01	1945
2013-01-01	985
2013-04-01	1570
2013-07-01	-2478
2013-10-01	-291
2014-01-01	-500
2014-04-01	90
2014-07-01	-771
2014-10-01	5375
2015-01-01	-3368
2015-04-01	-859
2015-07-01	4752
2015-10-01	-2155
2016-01-01	4053
2016-04-01	-4211
2016-07-01	-2163
2016-10-01	-1352
2017-01-01	-758
2017-04-01	4153
2017-07-01	1329
2017-10-01	-171
2018-01-01	-597
2018-04-01	1654