Quarter	Billions of US Dollars
1987-01-01	0.1530
1987-04-01	0.1490
1987-07-01	0.2000
1987-10-01	0.2270
1988-01-01	0.3360
1988-04-01	0.4670
1988-07-01	0.4740
1988-10-01	0.4570
1989-01-01	0.6130
1989-04-01	0.6120
1989-07-01	0.5570
1989-10-01	0.5250
1990-01-01	0.4270
1990-04-01	0.3730
1990-07-01	0.5360
1990-10-01	0.4100
1991-01-01	0.5700
1991-04-01	0.3160
1991-07-01	0.3140
1991-10-01	0.3160
1992-01-01	0.4660
1992-04-01	0.4910
1992-07-01	0.5360
1992-10-01	0.6010
1993-01-01	0.5040
1993-04-01	0.5690
1993-07-01	0.3123
1993-10-01	0.4002
1994-01-01	0.3786
1994-04-01	0.3576
1994-07-01	0.3248
1994-10-01	0.2342
1995-01-01	0.2931
1995-04-01	0.2807
1995-07-01	0.4434
1995-10-01	0.2610
1996-01-01	0.2662
1996-04-01	0.4390
1996-07-01	0.8814
1996-10-01	1.1538
1997-01-01	1.8993
1997-04-01	2.5508
1997-07-01	2.5007
1997-10-01	2.4133
1998-01-01	2.4834
1998-04-01	2.3547
1998-07-01	2.7201
1998-10-01	3.0943
1999-01-01	5.2795
1999-04-01	3.1470
1999-07-01	5.0936
1999-10-01	4.9516
2000-01-01	2.9475
2000-04-01	2.6997
2000-07-01	3.0976
2000-10-01	3.0815
2001-01-01	3.0552
2001-04-01	3.1767
2001-07-01	2.9724
2001-10-01	2.8606
2002-01-01	3.0761
2002-04-01	3.1590
2002-07-01	3.2732
2002-10-01	2.3822
2003-01-01	2.1541
2003-04-01	1.3603
2003-07-01	1.1484
2003-10-01	1.2359
2004-01-01	1.2038
2004-04-01	1.1549
2004-07-01	1.5218
2004-10-01	1.3911
2005-01-01	1.6095
2005-04-01	1.5171
2005-07-01	0.7489
2005-10-01	1.0501
2006-01-01	1.6016
2006-04-01	1.8845
2006-07-01	2.1932
2006-10-01	1.8284
2007-01-01	1.4905
2007-04-01	1.4938
2007-07-01	1.3690
2007-10-01	1.5251
2008-01-01	2.0454
2008-04-01	2.5135
2008-07-01	2.4634
2008-10-01	2.7205
2009-01-01	2.9257
2009-04-01	2.6674
2009-07-01	2.1976
2009-10-01	2.2122
2010-01-01	3.6291
2010-04-01	2.4641
2010-07-01	3.7337
2010-10-01	4.7262
2011-01-01	6.0647
2011-04-01	9.3297
2011-07-01	9.9771
2011-10-01	11.2925
2012-01-01	16.4527
2012-04-01	18.0363
2012-07-01	20.7587
2012-10-01	19.7950
2013-01-01	24.2707
2013-04-01	29.7365
2013-07-01	31.7158
2013-10-01	37.4713
2014-01-01	40.8972
2014-04-01	47.2601
2014-07-01	50.4143
2014-10-01	49.0469
2015-01-01	52.7104
2015-04-01	47.2848