Quarter	Millions of US Dollars
2003-01-01	500
2003-04-01	250
2008-01-01	-150
2008-04-01	-250
2009-04-01	750
2010-01-01	1250
2010-04-01	750
2011-10-01	750
2012-07-01	1500
2012-10-01	96
2013-01-01	-350
2013-04-01	49
2013-07-01	1500
2014-04-01	-750
2014-07-01	1250
2015-04-01	-750
2015-10-01	1500
2016-01-01	600
2016-10-01	2000
2017-01-01	1200
2017-07-01	5650
2017-10-01	-72
2018-04-01	962