Quarter	Billions of US Dollars
1997-10-01	10
1998-01-01	10
1998-04-01	5
1998-07-01	5
2014-04-01	0
2014-07-01	20
2014-10-01	30
2015-01-01	30
2015-04-01	40
2015-07-01	20
2015-10-01	0
2016-01-01	0
2016-04-01	0
2016-07-01	0
2016-10-01	0
2017-01-01	0
2017-04-01	0
2017-07-01	0
2017-10-01	0
2018-01-01	0
2018-04-01	750