Quarter	Millions of US Dollars
1997-07-01	30
1999-04-01	159
1999-10-01	78
2000-07-01	-30
2001-04-01	22
2001-10-01	181
2002-07-01	20
2004-04-01	228
2004-10-01	7
2005-04-01	125
2005-07-01	-24
2006-04-01	247
2006-10-01	-6
2007-04-01	-40
2008-01-01	605
2008-04-01	-156
2008-10-01	-263
2011-04-01	212
2012-01-01	1000
2012-10-01	1250
2014-01-01	2739
2014-04-01	823
2014-07-01	-697
2014-10-01	19
2015-04-01	0
2015-07-01	556
2015-10-01	602
2016-01-01	0
2016-04-01	848
2016-10-01	1484
2017-01-01	-147
2017-04-01	1383
2017-07-01	-352
2017-10-01	23
2018-01-01	-492
2018-04-01	1128