Quarter	Millions of US Dollars
2007-07-01	275
2007-10-01	276
2008-01-01	277
2008-04-01	277
2008-07-01	278
2008-10-01	279
2009-01-01	279
2009-04-01	280
2009-07-01	281
2009-10-01	281
2010-01-01	282
2010-04-01	283
2011-04-01	400
2011-07-01	400
2011-10-01	400
2012-01-01	400
2012-04-01	400
2012-07-01	1245
2012-10-01	1245
2013-01-01	1545
2013-04-01	1545
2013-07-01	1880
2013-10-01	1880
2014-01-01	2105
2014-04-01	2285
2014-07-01	2708
2014-10-01	2803
2015-01-01	4083
2015-04-01	4083
2015-07-01	4077
2015-10-01	4073
2016-01-01	4074
2016-04-01	4345
2016-07-01	4345
2016-10-01	4321
2017-01-01	4432
2017-04-01	5434
2017-07-01	5243
2017-10-01	5867
2018-01-01	6104
2018-04-01	6505