Quarter	Billions of US Dollars
1987-01-01	0.10000
1987-04-01	0.11870
1988-10-01	-0.00100
1989-04-01	-0.05827
1989-07-01	-0.07100
1990-07-01	-0.06276
1990-10-01	-0.12000
1992-01-01	-0.10300
1992-04-01	-0.07583
1993-10-01	-0.08915
1995-10-01	-0.08535
1996-01-01	-0.02000
1996-07-01	0.07500
1997-01-01	-0.10000
1997-07-01	0.11500
1997-10-01	0.00000
1998-07-01	-0.07500
2002-07-01	-0.11500
2005-10-01	0.15000
2007-10-01	0.15944
2010-04-01	0.10638
2010-07-01	0.03042
2010-10-01	-0.13303
2011-01-01	-0.02153
2011-04-01	0.24890
2011-07-01	0.25357
2011-10-01	-0.13074
2012-01-01	0.01490
2012-04-01	0.37355
2012-07-01	-0.00198
2012-10-01	0.38264
2013-01-01	0.00699
2013-04-01	0.20978
2013-07-01	0.07644
2013-10-01	-0.05228
2014-01-01	0.19854
2014-04-01	0.51837
2014-07-01	0.00060
2014-10-01	0.41671
2015-01-01	0.11820
2015-04-01	0.15393