Quarter	Billions of US Dollars
1987-01-01	0.205
1987-04-01	0.303
1987-07-01	0.388
1987-10-01	0.492
1988-01-01	0.503
1988-04-01	0.485
1988-07-01	0.475
1988-10-01	0.489
1989-01-01	0.448
1989-04-01	0.428
1989-07-01	0.588
1989-10-01	0.534
1990-01-01	0.647
1990-04-01	0.976
1990-07-01	1.072
1990-10-01	0.828
1991-01-01	0.940
1991-04-01	1.557
1991-07-01	1.499
1991-10-01	1.605
1992-01-01	1.610
1992-04-01	1.608
1992-07-01	1.927
1992-10-01	2.223
1993-01-01	1.347
1993-04-01	1.517
1993-07-01	1.608
1993-10-01	1.539
1994-01-01	1.167
1994-04-01	0.732
1994-07-01	0.564
1994-10-01	0.609
1995-01-01	0.670
1995-04-01	0.860
1995-07-01	0.970
1995-10-01	0.836
1996-01-01	0.664
1996-04-01	0.702
1996-07-01	0.788
1996-10-01	0.545
1997-01-01	0.705
1997-04-01	0.937
1997-07-01	1.023
1997-10-01	0.827
1998-01-01	0.713
1998-04-01	0.744
1998-07-01	0.831
1998-10-01	0.824
1999-01-01	1.830
1999-04-01	1.851
1999-07-01	4.821
1999-10-01	7.449
2000-01-01	5.936
2000-04-01	6.931
2000-07-01	8.114
2000-10-01	8.151
2001-01-01	7.576
2001-04-01	9.461
2001-07-01	10.467
2001-10-01	10.939
2002-01-01	13.015
2002-04-01	14.806
2002-07-01	17.008
2002-10-01	24.348
2003-01-01	33.092
2003-04-01	40.682
2003-07-01	47.998
2003-10-01	58.487
2004-01-01	65.669
2004-04-01	65.180
2004-07-01	67.151
2004-10-01	82.807
2005-01-01	93.482
2005-04-01	109.077
2005-07-01	111.630
2005-10-01	141.086
2006-01-01	184.693
2006-04-01	213.096
2006-07-01	228.974
2006-10-01	244.975
2007-01-01	282.949
2007-04-01	308.854
2007-07-01	327.780
2007-10-01	339.945
2008-01-01	352.826
2008-04-01	383.234
2008-07-01	363.249
2008-10-01	330.494
2009-01-01	319.908
2009-04-01	338.827
2009-07-01	346.084
2009-10-01	349.946
2010-01-01	321.468
2010-04-01	271.824
2010-07-01	313.667
2010-10-01	299.242
2011-01-01	305.222
2011-04-01	287.473
2011-07-01	263.469
2011-10-01	245.236
2012-01-01	253.880
2012-04-01	211.503
2012-07-01	207.253
2012-10-01	203.835
2013-01-01	189.152
2013-04-01	191.213
2013-07-01	181.187
2013-10-01	185.514
2014-01-01	179.264
2014-04-01	181.290
2014-07-01	162.134
2014-10-01	149.889
2015-01-01	133.087
2015-04-01	131.619