Quarter	Millions of US Dollars
2001-04-01	682
2001-07-01	561
2001-10-01	-42
2002-01-01	-783
2002-04-01	46
2002-07-01	427
2002-10-01	653
2003-01-01	962
2003-04-01	1159
2003-07-01	806
2003-10-01	-538
2004-01-01	547
2004-04-01	268
2004-07-01	2482
2004-10-01	2932
2005-01-01	909
2005-04-01	978
2005-07-01	1382
2005-10-01	1378
2006-01-01	1237
2006-04-01	2064
2006-07-01	3300
2006-10-01	1790
2007-01-01	2110
2007-04-01	1964
2007-07-01	2927
2007-10-01	1475
2008-01-01	555
2008-04-01	1811
2008-07-01	1274
2008-10-01	-209
2009-01-01	1830
2009-04-01	-2041
2009-07-01	919
2009-10-01	-931
2010-01-01	1118
2010-04-01	1975
2010-07-01	-576
2010-10-01	-309
2011-01-01	4296
2011-04-01	65
2011-07-01	1350
2011-10-01	-177
2012-01-01	3277
2012-04-01	2045
2012-07-01	433
2012-10-01	188
2013-01-01	883
2013-04-01	643
2013-07-01	-374
2013-10-01	295
2014-01-01	1028
2014-04-01	1315
2014-07-01	208
2014-10-01	568
2015-01-01	1306
2015-04-01	694
2015-07-01	71
2015-10-01	984
2016-01-01	-713
2016-04-01	582
2016-07-01	178
2016-10-01	-75
2017-01-01	1385
2017-04-01	1015
2017-07-01	710
2017-10-01	901
2018-01-01	100