Quarter	Millions of US Dollars
2010-07-01	4971
2010-10-01	-6294
2011-01-01	10456
2011-04-01	-5195
2011-07-01	-1339
2011-10-01	-5897
2012-01-01	4095
2012-04-01	2607
2012-07-01	3732
2012-10-01	2158
2013-01-01	5983
2013-04-01	667
2013-07-01	2142
2013-10-01	1496
2014-01-01	4375
2014-04-01	2594
2014-07-01	-18129
2014-10-01	606
2015-01-01	3075
2015-04-01	225
2015-07-01	2933
2015-10-01	-1257
2016-01-01	4595
2016-04-01	-749
2016-07-01	2878
2016-10-01	-771
2017-01-01	3612
2017-04-01	1587
2017-07-01	3083
2017-10-01	1924
2018-01-01	3773