Quarter	Billions of US Dollars
1987-01-01	0.19150
1987-07-01	0.11650
1988-01-01	0.11240
1988-04-01	0.15760
1988-07-01	0.11340
1988-10-01	0.08260
1990-07-01	-0.03862
1991-10-01	0.02240
1992-01-01	-0.15549
1992-04-01	0.11093
1992-07-01	0.07000
1992-10-01	0.24000
1993-01-01	-0.28923
1993-04-01	0.30000
1993-07-01	0.66374
1993-10-01	-0.00920
1994-01-01	-0.09292
1994-04-01	0.12620
1994-07-01	0.28000
1994-10-01	0.33600
1995-01-01	-0.31166
1995-07-01	0.71420
1995-10-01	-0.19856
1996-01-01	-0.77798
1996-07-01	0.63666
1996-10-01	0.04842
1997-01-01	0.10651
1997-04-01	0.41000
1997-07-01	0.03041
1997-10-01	-0.02635
1998-01-01	0.01000
1998-04-01	-0.19100
1998-07-01	-0.15143
1998-10-01	-0.23690
1999-01-01	-0.05000
1999-04-01	-0.10749
1999-10-01	-0.28698
2000-01-01	-0.08900
2000-04-01	-0.03000
2000-07-01	-0.46480
2001-01-01	-0.15000
2001-07-01	-0.56749
2001-10-01	-0.21836
2002-01-01	-0.03000
2002-04-01	-0.40000
2002-07-01	-0.18450
2003-07-01	-0.37758
2004-07-01	-0.12738
2005-01-01	-0.09550
2006-04-01	-0.09700
2006-07-01	-0.12050
2006-10-01	-0.20000
2007-07-01	-0.18491
2009-04-01	-0.02342
2009-10-01	0.87900
2010-07-01	0.39771
2011-01-01	0.52451
2011-04-01	1.45382
2011-10-01	-0.15769
2012-01-01	0.47914
2012-07-01	0.26014
2012-10-01	1.98105
2013-01-01	0.72037
2013-04-01	1.55000
2013-07-01	1.00000
2013-10-01	1.82585
2014-01-01	0.12842
2014-04-01	0.63119
2014-07-01	0.37173
2014-10-01	0.31966
2015-01-01	0.03700
2015-04-01	2.81376