Quarter	Billions of US Dollars
1997-04-01	0.05
2000-04-01	-0.05
2002-07-01	0.35
2007-10-01	0.50
2009-10-01	0.50
2010-10-01	1.00
2011-07-01	1.00
2012-07-01	1.00
2012-10-01	-0.50
2014-01-01	1.00
2014-04-01	0.50
2015-01-01	-0.50
2015-04-01	0.65