Quarter	Millions of US Dollars
1996-01-01	-76
1996-04-01	-51
1996-07-01	246
1996-10-01	340
1997-01-01	412
1997-04-01	272
1997-07-01	229
1997-10-01	-202
1998-01-01	-241
1998-04-01	136
1998-07-01	-331
1998-10-01	-147
1999-01-01	529
1999-04-01	456
1999-07-01	70
1999-10-01	66
2000-01-01	346
2000-04-01	195
2000-07-01	595
2000-10-01	-157
2001-01-01	740
2001-04-01	292
2001-07-01	119
2001-10-01	-268
2002-01-01	741
2002-04-01	861
2002-07-01	-61
2002-10-01	1314
2003-01-01	-307
2003-04-01	660
2003-07-01	-238
2003-10-01	238
2004-01-01	-335
2004-04-01	1023
2004-07-01	-46
2004-10-01	495
2005-01-01	527
2005-04-01	1299
2005-07-01	851
2005-10-01	-15
2006-01-01	526
2006-04-01	1086
2006-07-01	3274
2006-10-01	-1166
2007-01-01	1889
2007-04-01	1917
2007-07-01	-135
2007-10-01	174
2008-01-01	-1026
2008-04-01	268
2008-07-01	-680
2008-10-01	-2488
2009-01-01	1098
2009-04-01	351
2009-07-01	1280
2009-10-01	-125
2010-01-01	-31
2010-04-01	177
2010-07-01	-404
2010-10-01	985
2011-01-01	1253
2011-04-01	409
2011-07-01	-566
2011-10-01	-344
2012-01-01	-323
2012-04-01	777
2012-07-01	1819
2012-10-01	1980
2013-01-01	2111
2013-04-01	3928
2013-07-01	901
2013-10-01	268
2014-01-01	1684
2014-04-01	1842
2014-07-01	743
2014-10-01	-619
2015-01-01	-68
2015-04-01	1655
2015-07-01	-933
2015-10-01	-180
2016-01-01	-748
2016-04-01	935
2016-07-01	-557
2016-10-01	1388
2017-01-01	690
2017-04-01	848
2017-07-01	414
2017-10-01	2566
2018-01-01	1499