Quarter	Millions of US Dollars
2013-01-01	500
2013-04-01	500
2013-07-01	500
2013-10-01	500
2014-01-01	500
2014-04-01	500
2014-07-01	1500
2014-10-01	1500
2015-01-01	1500
2015-04-01	1780
2015-07-01	1780
2015-10-01	1780
2016-01-01	2380
2016-04-01	2380
2016-07-01	2380
2016-10-01	2380
2017-01-01	2880
2017-04-01	2880
2017-07-01	2880
2017-10-01	2880
2018-01-01	3410
2018-04-01	3410