Quarter	Billions of US Dollars
1987-01-01	0.8590
1987-04-01	0.7390
1987-07-01	0.8790
1987-10-01	0.8530
1988-01-01	0.7750
1988-04-01	0.6690
1988-07-01	0.9670
1988-10-01	0.9700
1989-01-01	1.3660
1989-04-01	1.1640
1989-07-01	1.3270
1989-10-01	1.0460
1990-01-01	1.4860
1990-04-01	1.6740
1990-07-01	1.8140
1990-10-01	1.2500
1991-01-01	1.6280
1991-04-01	1.6230
1991-07-01	1.3690
1991-10-01	1.3410
1992-01-01	1.5230
1992-04-01	1.6430
1992-07-01	2.0100
1992-10-01	1.6010
1993-01-01	1.5060
1993-04-01	1.1630
1993-07-01	0.6410
1993-10-01	0.7572
1994-01-01	0.6416
1994-04-01	0.6038
1994-07-01	0.8304
1994-10-01	0.7599
1995-01-01	0.7950
1995-04-01	0.7550
1995-07-01	0.7860
1995-10-01	0.6700
1996-01-01	0.9930
1996-04-01	0.9339
1996-07-01	0.8396
1996-10-01	1.2894
1997-01-01	1.2434
1997-04-01	1.2670
1997-07-01	1.1603
1997-10-01	1.0502
1998-01-01	0.8570
1998-04-01	0.9239
1998-07-01	1.0017
1998-10-01	0.8810
1999-01-01	1.6445
1999-04-01	1.9582
1999-07-01	2.4624
1999-10-01	2.7874
2000-01-01	6.0379
2000-04-01	5.8577
2000-07-01	6.0353
2000-10-01	4.1309
2001-01-01	7.0238
2001-04-01	6.9419
2001-07-01	5.4608
2001-10-01	3.3978
2002-01-01	4.2304
2002-04-01	5.1718
2002-07-01	3.8575
2002-10-01	2.1460
2003-01-01	5.7016
2003-04-01	5.2251
2003-07-01	3.1373
2003-10-01	2.8338
2004-01-01	5.3754
2004-04-01	6.1506
2004-07-01	7.6923
2004-10-01	5.4789
2005-01-01	9.0776
2005-04-01	10.4939
2005-07-01	10.3746
2005-10-01	8.5193
2006-01-01	15.4657
2006-04-01	17.6100
2006-07-01	14.6415
2006-10-01	11.1314
2007-01-01	20.8577
2007-04-01	30.5474
2007-07-01	34.3232
2007-10-01	16.3595
2008-01-01	25.6349
2008-04-01	23.1775
2008-07-01	23.6014
2008-10-01	28.2224
2009-01-01	27.4621
2009-04-01	21.3177
2009-07-01	16.8526
2009-10-01	13.2604
2010-01-01	14.7017
2010-04-01	13.3719
2010-07-01	14.7157
2010-10-01	12.4104
2011-01-01	25.0714
2011-04-01	19.8738
2011-07-01	21.0617
2011-10-01	17.2318
2012-01-01	17.2059
2012-04-01	14.8351
2012-07-01	14.7429
2012-10-01	16.3749
2013-01-01	18.0337
2013-04-01	12.5488
2013-07-01	17.6829
2013-10-01	18.7163
2014-01-01	20.6971
2014-04-01	20.9859
2014-07-01	18.2666
2014-10-01	17.2555
2015-01-01	16.8127
2015-04-01	13.9291