Quarter	Millions of US Dollars
2008-01-01	14
2008-04-01	26
2008-07-01	10
2009-04-01	-26
2011-07-01	-10
2012-01-01	500
2012-07-01	-14
2013-01-01	1000
2014-01-01	1250
2014-04-01	866
2014-07-01	10
2014-10-01	50
2015-01-01	868
2015-04-01	-1
2015-10-01	-50
2016-01-01	1251
2016-04-01	-14
2016-07-01	2
2017-01-01	2500
2017-04-01	-348
2017-07-01	5
2017-10-01	10
2018-04-01	-12