Quarter	Millions of US Dollars
2001-07-01	1500
2005-07-01	1250
2006-07-01	-500
2007-07-01	1055
2010-04-01	1500
2011-07-01	-1000
2012-07-01	-989
2013-04-01	2700
2013-07-01	1000
2014-10-01	-2700
2015-04-01	1637
2015-07-01	-1250
2015-10-01	1044
2016-07-01	-1000
2016-10-01	4158
2017-01-01	2079
2017-04-01	1628
2017-07-01	0
2017-10-01	-1318
2018-01-01	2803
2018-04-01	4901