Quarter	Millions of US Dollars
2002-04-01	237
2002-07-01	491
2002-10-01	1603
2003-01-01	-264
2003-04-01	-1670
2003-07-01	-191
2003-10-01	-719
2004-01-01	-419
2004-04-01	-491
2004-07-01	1360
2004-10-01	79
2005-01-01	1040
2005-04-01	894
2005-07-01	1703
2005-10-01	467
2006-01-01	875
2006-04-01	638
2006-07-01	3072
2006-10-01	3710
2007-01-01	1456
2007-04-01	2105
2007-07-01	3360
2007-10-01	2128
2008-01-01	3188
2008-04-01	5959
2008-07-01	7140
2008-10-01	3764
2009-01-01	-939
2009-04-01	381
2009-07-01	3238
2009-10-01	7041
2010-01-01	4687
2010-04-01	7463
2010-07-01	7134
2010-10-01	8592
2011-01-01	3672
2011-04-01	9012
2011-07-01	4964
2011-10-01	10748
2012-01-01	10674
2012-04-01	7429
2012-07-01	9507
2012-10-01	10711
2013-01-01	2021
2013-04-01	6116
2013-07-01	4804
2013-10-01	5816
2014-01-01	7051
2014-04-01	6094
2014-07-01	2462
2014-10-01	7065
2015-01-01	3567
2015-04-01	-5615
2015-07-01	1059
2015-10-01	574
2016-01-01	810
2016-04-01	-6805
2016-07-01	-2369
2016-10-01	5076
2017-01-01	32
2017-04-01	-395
2017-07-01	4461
2017-10-01	8153
2018-01-01	2804