Quarter	Billions of US Dollars
1987-01-01	0.8040
1987-04-01	0.8770
1987-07-01	0.5980
1987-10-01	0.5780
1988-01-01	0.6480
1988-04-01	0.6750
1988-07-01	0.6760
1988-10-01	0.6580
1989-01-01	0.7230
1989-04-01	0.8710
1989-07-01	0.7320
1989-10-01	0.5600
1990-01-01	0.8020
1990-04-01	0.7360
1990-07-01	0.7850
1990-10-01	0.4970
1991-01-01	0.5910
1991-04-01	0.5840
1991-07-01	0.5010
1991-10-01	0.3480
1992-01-01	0.3860
1992-04-01	0.4290
1992-07-01	0.3690
1992-10-01	0.1870
1993-01-01	0.5620
1993-04-01	0.3480
1993-07-01	0.5739
1993-10-01	0.5478
1994-01-01	0.6472
1994-04-01	0.6762
1994-07-01	0.5634
1994-10-01	0.5380
1995-01-01	0.5597
1995-04-01	1.2319
1995-07-01	1.9940
1995-10-01	2.4592
1996-01-01	2.4198
1996-04-01	2.7602
1996-07-01	4.4688
1996-10-01	5.8422
1997-01-01	5.5017
1997-04-01	5.0377
1997-07-01	4.1081
1997-10-01	2.0447
1998-01-01	1.5732
1998-04-01	1.9443
1998-07-01	1.3361
1998-10-01	1.2503
1999-01-01	1.3160
1999-04-01	1.0810
1999-07-01	1.1095
1999-10-01	1.3443
2000-01-01	1.5014
2000-04-01	2.3922
2000-07-01	2.6315
2000-10-01	2.5341
2001-01-01	1.7379
2001-04-01	1.9712
2001-07-01	1.5258
2001-10-01	1.2820
2002-01-01	0.9074
2002-04-01	1.2746
2002-07-01	2.4998
2002-10-01	2.2913
2003-01-01	2.4805
2003-04-01	2.2185
2003-07-01	2.4193
2003-10-01	2.7891
2004-01-01	2.7779
2004-04-01	2.4287
2004-07-01	2.6326
2004-10-01	3.3420
2005-01-01	3.7442
2005-04-01	4.3556
2005-07-01	2.9239
2005-10-01	3.3381
2006-01-01	3.8744
2006-04-01	4.9157
2006-07-01	6.0595
2006-10-01	5.6364
2007-01-01	6.2407
2007-04-01	6.5072
2007-07-01	7.7112
2007-10-01	8.0019
2008-01-01	9.4253
2008-04-01	11.2288
2008-07-01	10.4470
2008-10-01	4.6296
2009-01-01	4.8068
2009-04-01	7.5701
2009-07-01	8.7677
2009-10-01	8.7811
2010-01-01	8.6213
2010-04-01	8.3529
2010-07-01	8.5375
2010-10-01	7.6352
2011-01-01	9.0725
2011-04-01	11.9774
2011-07-01	13.2207
2011-10-01	16.6715
2012-01-01	26.8071
2012-04-01	29.3209
2012-07-01	29.8942
2012-10-01	33.5877
2013-01-01	40.5323
2013-04-01	46.3981
2013-07-01	55.8217
2013-10-01	63.8507
2014-01-01	79.1003
2014-04-01	90.1513
2014-07-01	95.3781
2014-10-01	92.4676
2015-01-01	90.5957
2015-04-01	87.4286