Quarter	Millions of US Dollars
2002-07-01	4813
2002-10-01	15026
2003-01-01	6248
2003-04-01	7379
2003-07-01	-323
2003-10-01	15952
2004-01-01	12933
2004-04-01	9381
2004-07-01	4270
2004-10-01	27703
2005-01-01	26951
2005-04-01	15026
2005-07-01	7375
2005-10-01	5159
2006-01-01	17289
2006-04-01	34674
2006-07-01	16185
2006-10-01	8516
2007-01-01	30311
2007-04-01	22140
2007-07-01	5077
2007-10-01	10634
2008-01-01	22634
2008-04-01	22124
2008-07-01	-491
2008-10-01	14138
2009-01-01	48456
2009-04-01	42368
2009-07-01	30384
2009-10-01	7207
2010-01-01	39508
2010-04-01	22482
2010-07-01	17509
2010-10-01	209
2011-01-01	29532
2011-04-01	22008
2011-07-01	15850
2011-10-01	10863
2012-01-01	30108
2012-04-01	16185
2012-07-01	21665
2012-10-01	14937
2013-01-01	38197
2013-04-01	28843
2013-07-01	16155
2013-10-01	19756
2014-01-01	24279
2014-04-01	25889
2014-07-01	8771
2014-10-01	19012
2015-01-01	37289
2015-04-01	47660
2015-07-01	15122
2015-10-01	-317
2016-01-01	28369
2016-04-01	16773
2016-07-01	4401
2016-10-01	-11670
2017-01-01	26782
2017-04-01	32701
2017-07-01	3512
2017-10-01	13188
2018-01-01	35588