Quarter	Millions of US Dollars
1999-07-01	0
1999-10-01	21560
2000-01-01	311
2000-04-01	10860
2000-07-01	3049
2000-10-01	2011
2001-01-01	140
2001-04-01	204
2001-07-01	275
2001-10-01	-997
2002-01-01	276
2002-04-01	199
2002-07-01	-154
2002-10-01	-441
2003-01-01	-641
2003-04-01	-401
2003-07-01	-270
2003-10-01	915
2004-01-01	-250
2004-04-01	-300
2004-07-01	1036
2004-10-01	463
2005-01-01	943
2005-04-01	-333
2005-07-01	137
2005-10-01	-667
2006-01-01	-24
2006-04-01	829
2006-07-01	1890
2006-10-01	-664
2007-01-01	2200
2007-04-01	1770
2007-07-01	1924
2007-10-01	568
2008-01-01	2571
2008-04-01	2038
2008-07-01	1776
2008-10-01	-59
2009-01-01	984
2009-04-01	586
2009-07-01	1744
2009-10-01	1171
2010-01-01	1258
2010-04-01	3096
2010-07-01	2674
2010-10-01	-430
2011-01-01	3871
2011-04-01	1880
2011-07-01	609
2011-10-01	2837
2012-01-01	4177
2012-04-01	3243
2012-07-01	-4126
2012-10-01	7119
2013-01-01	4243
2013-04-01	2721
2013-07-01	4758
2013-10-01	4500
2014-01-01	7159
2014-04-01	6105
2014-07-01	5113
2014-10-01	1356
2015-01-01	7033
2015-04-01	3799
2015-07-01	2722
2015-10-01	4895
2016-01-01	8542
2016-04-01	5763
2016-07-01	8038
2016-10-01	1818
2017-01-01	8832
2017-04-01	3952
2017-07-01	6631
2017-10-01	3743
2018-01-01	6175