Quarter	Millions of US Dollars
1977-01-01	42
1982-01-01	-43
2007-07-01	1000
2008-04-01	1770
2009-04-01	6000
2010-10-01	1435
2011-04-01	500
2012-07-01	-1000
2013-04-01	-1770
2014-04-01	-3042
2014-07-01	3
2014-10-01	-3
2015-01-01	914
2015-04-01	-3
2015-07-01	-1
2015-10-01	-500
2016-01-01	480
2016-04-01	9408
2016-07-01	134
2016-10-01	36
2017-01-01	64
2017-04-01	20
2017-07-01	4
2017-10-01	10048
2018-01-01	604
2018-04-01	1