Quarter	Millions of US Dollars
1996-10-01	200
1997-01-01	200
1997-04-01	200
1997-07-01	200
1997-10-01	550
1998-01-01	550
1998-04-01	550
1998-07-01	550
1998-10-01	550
1999-01-01	550
1999-04-01	550
1999-07-01	550
1999-10-01	650
2000-01-01	650
2000-04-01	1000
2000-07-01	1000
2000-10-01	1000
2001-01-01	1000
2001-04-01	1000
2001-07-01	1150
2001-10-01	1150
2002-01-01	1150
2002-04-01	1150
2002-07-01	1150
2002-10-01	900
2003-01-01	900
2003-04-01	1000
2003-07-01	1000
2003-10-01	1000
2004-01-01	1200
2004-04-01	1500
2004-07-01	1500
2004-10-01	1600
2005-01-01	1800
2005-04-01	2400
2005-07-01	2400
2005-10-01	2850
2006-01-01	3271
2006-04-01	3821
2006-07-01	4504
2006-10-01	4797
2007-01-01	4806
2007-04-01	4408
2007-07-01	4453
2007-10-01	5136
2008-01-01	4967
2008-04-01	4693
2008-07-01	4620
2008-10-01	4482
2009-01-01	4108
2009-04-01	4155
2009-07-01	4696
2009-10-01	4777
2010-01-01	4728
2010-04-01	5240
2010-07-01	5323
2010-10-01	9115
2011-01-01	10207
2011-04-01	10480
2011-07-01	9766
2011-10-01	9721
2012-01-01	9755
2012-04-01	9797
2012-07-01	10682
2012-10-01	12456
2013-01-01	13420
2013-04-01	17179
2013-07-01	17679
2013-10-01	18164
2014-01-01	18168
2014-04-01	20084
2014-07-01	19020
2014-10-01	25704
2015-01-01	24974
2015-04-01	24178
2015-07-01	28835
2015-10-01	27382
2016-01-01	31530
2016-04-01	27299
2016-07-01	25661
2016-10-01	24614
2017-01-01	24782
2017-04-01	27041
2017-07-01	27680
2017-10-01	27625
2018-01-01	27650
2018-04-01	29164