Quarter	Billions of US Dollars
1987-01-01	0.2581
1987-04-01	0.2570
1987-07-01	0.2566
1987-10-01	0.2698
1988-01-01	0.2654
1988-04-01	0.2574
1988-07-01	0.2548
1988-10-01	0.2593
1989-01-01	0.2543
1989-04-01	0.2262
1989-07-01	0.2285
1989-10-01	0.2339
1990-01-01	0.2340
1990-04-01	0.2348
1990-07-01	0.6136
1990-10-01	0.6275
1991-01-01	0.5803
1991-04-01	0.5545
1991-07-01	0.5606
1991-10-01	0.5901
1992-01-01	0.5587
1992-04-01	0.5951
1992-07-01	0.5775
1992-10-01	0.5144
1993-01-01	0.5126
1993-04-01	0.5110
1993-07-01	0.5139
1993-10-01	0.5042
1994-01-01	0.5062
1994-04-01	0.6437
1994-07-01	0.5305
1994-10-01	1.5297
1995-01-01	1.6641
1995-04-01	1.7231
1995-07-01	1.5538
1995-10-01	1.1225
1996-01-01	1.0909
1996-04-01	1.0639
1996-07-01	1.0511
1996-10-01	1.1018
1997-01-01	1.0393
1997-04-01	1.1591
1997-07-01	1.1724
1997-10-01	1.1142
1998-01-01	1.0970
1998-04-01	0.3412
1998-07-01	0.8694
1998-10-01	1.0217
1999-01-01	1.0239
1999-04-01	1.5945
1999-07-01	2.2154
1999-10-01	2.1519
2000-01-01	2.0556
2000-04-01	2.0339
2000-07-01	2.1493
2000-10-01	2.1706
2001-01-01	2.6957
2001-04-01	1.9094
2001-07-01	2.0569
2001-10-01	2.1227
2002-01-01	2.1166
2002-04-01	2.2247
2002-07-01	2.3378
2002-10-01	2.2779
2003-01-01	2.0573
2003-04-01	2.3617
2003-07-01	2.3329
2003-10-01	1.8884
2004-01-01	1.5538
2004-04-01	1.7698
2004-07-01	2.1989
2004-10-01	2.0674
2005-01-01	1.6832
2005-04-01	1.6846
2005-07-01	1.9385
2005-10-01	2.1453
2006-01-01	2.2099
2006-04-01	2.3341
2006-07-01	1.8113
2006-10-01	1.6206
2007-01-01	2.1027
2007-04-01	3.9408
2007-07-01	3.7884
2007-10-01	4.5448
2008-01-01	4.6014
2008-04-01	5.1239
2008-07-01	4.9766
2008-10-01	4.9873
2009-01-01	4.5102
2009-04-01	5.5110
2009-07-01	5.7317
2009-10-01	5.9956
2010-01-01	6.0142
2010-04-01	5.7509
2010-07-01	6.2971
2010-10-01	6.3487
2011-01-01	7.3910
2011-04-01	7.8024
2011-07-01	8.1461
2011-10-01	9.2861
2012-01-01	11.3536
2012-04-01	12.0600
2012-07-01	12.2177
2012-10-01	12.5278
2013-01-01	14.0936
2013-04-01	12.8590
2013-07-01	14.0001
2013-10-01	13.8427
2014-01-01	13.5023
2014-04-01	14.8137
2014-07-01	16.3879
2014-10-01	16.6657
2015-01-01	15.9934
2015-04-01	17.2532