Quarter	Millions of US Dollars
2001-07-01	150
2001-10-01	150
2002-01-01	150
2002-04-01	150
2002-07-01	150
2002-10-01	150
2003-01-01	150
2003-04-01	150
2003-07-01	150
2003-10-01	150
2004-01-01	150
2004-04-01	150
2004-07-01	150
2004-10-01	150
2005-01-01	150
2005-04-01	150
2005-07-01	150
2005-10-01	150
2006-01-01	150
2006-04-01	150
2010-04-01	500
2010-07-01	500
2010-10-01	3000
2011-01-01	3000
2011-04-01	3000
2011-07-01	3000
2011-10-01	3000
2012-01-01	3000
2012-04-01	3000
2012-07-01	3800
2012-10-01	4600
2013-01-01	4600
2013-04-01	7700
2013-07-01	7700
2013-10-01	7900
2014-01-01	7900
2014-04-01	8944
2014-07-01	8872
2014-10-01	12677
2015-01-01	12262
2015-04-01	11800
2015-07-01	11898
2015-10-01	11773
2016-01-01	11813
2016-04-01	11791
2016-07-01	10220
2016-10-01	9910
2017-01-01	9940
2017-04-01	12401
2017-07-01	13126
2017-10-01	12738
2018-01-01	12790
2018-04-01	14398