Quarter	Billions of US Dollars
1987-01-01	0.6166
1987-04-01	0.6155
1987-07-01	0.6100
1987-10-01	0.6426
1988-01-01	0.6968
1988-04-01	0.7434
1988-07-01	0.7320
1988-10-01	0.7512
1989-01-01	0.8045
1989-04-01	0.7171
1989-07-01	0.6300
1989-10-01	0.5880
1990-01-01	0.5837
1990-04-01	0.5928
1990-07-01	0.7884
1990-10-01	0.8083
1991-01-01	0.7378
1991-04-01	0.7135
1991-07-01	0.6542
1991-10-01	0.6029
1992-01-01	0.7130
1992-04-01	0.7485
1992-07-01	0.7925
1992-10-01	0.7264
1993-01-01	0.8412
1993-04-01	0.7215
1993-07-01	1.0492
1993-10-01	1.0663
1994-01-01	1.1284
1994-04-01	1.2340
1994-07-01	1.3475
1994-10-01	1.5406
1995-01-01	1.7637
1995-04-01	1.8672
1995-07-01	1.6962
1995-10-01	1.6843
1996-01-01	1.5985
1996-04-01	1.7477
1996-07-01	1.7462
1996-10-01	1.8315
1997-01-01	1.7746
1997-04-01	1.8501
1997-07-01	1.7391
1997-10-01	1.7730
1998-01-01	1.9288
1998-04-01	1.9517
1998-07-01	1.9436
1998-10-01	2.1860
1999-01-01	2.2302
1999-04-01	2.1215
1999-07-01	2.2764
1999-10-01	2.5781
2000-01-01	2.5441
2000-04-01	2.7659
2000-07-01	2.6752
2000-10-01	2.7149
2001-01-01	2.9586
2001-04-01	2.9598
2001-07-01	3.4579
2001-10-01	3.6710
2002-01-01	4.0860
2002-04-01	4.6535
2002-07-01	5.3067
2002-10-01	6.0828
2003-01-01	6.3515
2003-04-01	6.9893
2003-07-01	7.3087
2003-10-01	7.7829
2004-01-01	8.0475
2004-04-01	7.7006
2004-07-01	7.8935
2004-10-01	8.5535
2005-01-01	8.6527
2005-04-01	8.1432
2005-07-01	8.0008
2005-10-01	8.1711
2006-01-01	7.8202
2006-04-01	10.1987
2006-07-01	10.0419
2006-10-01	12.1436
2007-01-01	16.8401
2007-04-01	30.9270
2007-07-01	30.5638
2007-10-01	33.3194
2008-01-01	38.3768
2008-04-01	38.3589
2008-07-01	35.5221
2008-10-01	34.5200
2009-01-01	34.9353
2009-04-01	38.4368
2009-07-01	40.6712
2009-10-01	41.5654
2010-01-01	42.4046
2010-04-01	42.2004
2010-07-01	49.1115
2010-10-01	49.0338
2011-01-01	52.5159
2011-04-01	52.5641
2011-07-01	51.0176
2011-10-01	49.2124
2012-01-01	51.5726
2012-04-01	50.5204
2012-07-01	53.6446
2012-10-01	55.1888
2013-01-01	54.9602
2013-04-01	54.2003
2013-07-01	54.3887
2013-10-01	54.3061
2014-01-01	54.8611
2014-04-01	53.8200
2014-07-01	50.2796
2014-10-01	48.0778
2015-01-01	44.8551
2015-04-01	46.6052