Quarter	Millions of US Dollars
2006-10-01	52
2007-01-01	52
2007-04-01	52
2007-07-01	52
2007-10-01	98
2008-01-01	98
2008-04-01	98
2008-07-01	155
2008-10-01	155
2009-01-01	155
2009-04-01	155
2009-07-01	155
2009-10-01	155
2010-01-01	155
2010-04-01	155
2010-07-01	155
2010-10-01	155
2011-01-01	155
2011-04-01	155
2011-07-01	155
2011-10-01	155
2012-01-01	155
2012-04-01	155
2012-07-01	408
2012-10-01	408
2013-01-01	408
2013-04-01	408
2013-07-01	351
2013-10-01	351
2014-01-01	351
2014-04-01	351
2014-07-01	351
2014-10-01	351
2015-01-01	351
2015-04-01	351
2015-07-01	351
2015-10-01	351
2016-01-01	351
2016-04-01	351
2016-07-01	351
2016-10-01	351
2017-01-01	351
2017-04-01	351
2017-07-01	351
2017-10-01	351
2018-01-01	351
2018-04-01	351