Quarter	Billions of US Dollars
1997-01-01	0.00600
1997-04-01	0.01103
1997-07-01	0.01103
1997-10-01	0.01103
1998-01-01	0.00503
2006-10-01	0.05232
2007-01-01	0.05232
2007-04-01	0.05232
2007-07-01	0.05232
2008-01-01	0.09222
2008-04-01	0.19010
2008-07-01	0.16932
2008-10-01	0.16521
2009-01-01	0.20911
2009-04-01	0.17887
2009-07-01	0.18498
2009-10-01	0.18214
2010-01-01	0.00926
2010-04-01	0.24972
2010-07-01	0.27749
2010-10-01	0.28736
2011-01-01	0.29515
2011-04-01	0.29962
2011-07-01	0.27735
2011-10-01	0.26570
2012-01-01	0.27682
2015-04-01	0.21492