Quarter	Millions of US Dollars
2001-04-01	192
2001-07-01	59
2001-10-01	225
2002-01-01	300
2002-04-01	-310
2002-07-01	272
2002-10-01	-258
2003-01-01	199
2003-04-01	-48
2003-07-01	310
2003-10-01	453
2004-01-01	-245
2004-04-01	20
2004-07-01	774
2004-10-01	609
2005-01-01	73
2005-04-01	732
2005-07-01	-32
2005-10-01	-444
2006-01-01	81
2006-04-01	609
2006-07-01	1067
2006-10-01	468
2007-01-01	569
2007-04-01	275
2007-07-01	16
2007-10-01	930
2008-01-01	-404
2008-04-01	-295
2008-07-01	2257
2008-10-01	914
2009-01-01	991
2009-04-01	942
2009-07-01	1746
2009-10-01	1207
2010-01-01	1215
2010-04-01	1044
2010-07-01	1237
2010-10-01	1069
2011-01-01	129
2011-04-01	643
2011-07-01	-175
2011-10-01	169
2012-01-01	280
2012-04-01	1038
2012-07-01	796
2012-10-01	1079
2013-01-01	1039
2013-04-01	857
2013-07-01	627
2013-10-01	788
2014-01-01	30
2014-04-01	723
2014-07-01	39
2014-10-01	474
2015-01-01	479
2015-04-01	772
2015-07-01	-142
2015-10-01	249
2016-01-01	99
2016-04-01	67
2016-07-01	718
2016-10-01	-160
2017-01-01	247
2017-04-01	165
2017-07-01	367
2017-10-01	-265
2018-01-01	27