Quarter	Billions of US Dollars
1987-01-01	1.641
1987-04-01	1.421
1987-07-01	1.260
1987-10-01	1.200
1988-01-01	1.438
1988-04-01	1.495
1988-07-01	1.301
1988-10-01	1.379
1989-01-01	1.430
1989-04-01	1.570
1989-07-01	1.371
1989-10-01	1.071
1990-01-01	1.320
1990-04-01	1.263
1990-07-01	1.517
1990-10-01	2.139
1991-01-01	0.937
1991-04-01	1.008
1991-07-01	1.088
1991-10-01	1.591
1992-01-01	1.287
1992-04-01	1.426
1992-07-01	2.443
1992-10-01	2.623
1993-01-01	3.215
1993-04-01	4.428
1993-07-01	9.559
1993-10-01	9.577
1994-01-01	11.063
1994-04-01	11.334
1994-07-01	11.810
1994-10-01	10.420
1995-01-01	5.822
1995-04-01	6.873
1995-07-01	9.701
1995-10-01	11.119
1996-01-01	13.544
1996-04-01	16.885
1996-07-01	14.809
1996-10-01	16.096
1997-01-01	15.675
1997-04-01	14.775
1997-07-01	15.302
1997-10-01	11.146
1998-01-01	12.936
1998-04-01	13.261
1998-07-01	9.867
1998-10-01	7.128
1999-01-01	5.708
1999-04-01	6.227
1999-07-01	6.006
1999-10-01	6.467
2000-01-01	7.403
2000-04-01	7.250
2000-07-01	7.840
2000-10-01	9.121
2001-01-01	7.928
2001-04-01	8.026
2001-07-01	4.329
2001-10-01	3.832
2002-01-01	3.159
2002-04-01	3.171
2002-07-01	4.245
2002-10-01	4.689
2003-01-01	7.171
2003-04-01	6.878
2003-07-01	7.425
2003-10-01	6.860
2004-01-01	5.891
2004-04-01	5.196
2004-07-01	5.112
2004-10-01	6.403
2005-01-01	6.399
2005-04-01	7.161
2005-07-01	6.188
2005-10-01	7.350
2006-01-01	10.042
2006-04-01	11.344
2006-07-01	13.784
2006-10-01	14.501
2007-01-01	18.445
2007-04-01	19.939
2007-07-01	18.173
2007-10-01	18.960
2008-01-01	22.509
2008-04-01	24.811
2008-07-01	24.944
2008-10-01	13.959
2009-01-01	12.827
2009-04-01	14.472
2009-07-01	16.532
2009-10-01	14.895
2010-01-01	14.484
2010-04-01	14.462
2010-07-01	14.722
2010-10-01	13.188
2011-01-01	14.604
2011-04-01	19.066
2011-07-01	21.248
2011-10-01	25.051
2012-01-01	40.714
2012-04-01	47.053
2012-07-01	49.628
2012-10-01	55.828
2013-01-01	66.104
2013-04-01	73.764
2013-07-01	83.785
2013-10-01	90.055
2014-01-01	104.707
2014-04-01	118.363
2014-07-01	121.368
2014-10-01	120.005
2015-01-01	117.547
2015-04-01	117.893