Quarter	Millions of US Dollars
2008-01-01	6181
2008-04-01	-1069
2008-07-01	-2659
2008-10-01	-2483
2009-01-01	-397
2009-04-01	-2514
2009-07-01	874
2009-10-01	701
2010-01-01	2720
2010-04-01	-1476
2010-07-01	4438
2010-10-01	-2123
2011-01-01	225
2011-04-01	-3063
2011-07-01	195
2011-10-01	346
2012-01-01	3899
2012-04-01	-1231
2012-07-01	729
2012-10-01	1905
2013-01-01	2569
2013-04-01	-11
2013-07-01	-3007
2013-10-01	-3085
2014-01-01	-1554
2014-04-01	653
2014-07-01	461
2014-10-01	-667
2015-01-01	936
2015-04-01	-489
2015-07-01	858
2015-10-01	-911
2016-01-01	-188
2016-04-01	554
2016-07-01	3338
2016-10-01	-1287
2017-01-01	2769
2017-04-01	-1263
2017-07-01	2788
2017-10-01	-1486
2018-01-01	436