Quarter	Billions of US Dollars
1987-01-01	4.974
1987-04-01	5.428
1987-07-01	5.556
1987-10-01	5.963
1988-01-01	6.776
1988-04-01	7.409
1988-07-01	7.464
1988-10-01	8.132
1989-01-01	8.619
1989-04-01	8.204
1989-07-01	8.505
1989-10-01	10.155
1990-01-01	10.054
1990-04-01	11.065
1990-07-01	12.217
1990-10-01	12.169
1991-01-01	11.335
1991-04-01	12.409
1991-07-01	13.288
1991-10-01	14.004
1992-01-01	14.102
1992-04-01	15.063
1992-07-01	16.694
1992-10-01	15.725
1993-01-01	17.020
1993-04-01	17.802
1993-07-01	21.593
1993-10-01	22.229
1994-01-01	24.754
1994-04-01	26.244
1994-07-01	26.299
1994-10-01	26.037
1995-01-01	26.663
1995-04-01	26.057
1995-07-01	26.110
1995-10-01	26.027
1996-01-01	28.001
1996-04-01	28.082
1996-07-01	29.661
1996-10-01	30.641
1997-01-01	29.814
1997-04-01	30.726
1997-07-01	30.536
1997-10-01	29.826
1998-01-01	28.487
1998-04-01	27.683
1998-07-01	27.544
1998-10-01	28.526
1999-01-01	27.133
1999-04-01	28.681
1999-07-01	30.983
1999-10-01	32.316
2000-01-01	34.423
2000-04-01	36.468
2000-07-01	36.436
2000-10-01	36.484
2001-01-01	32.913
2001-04-01	32.034
2001-07-01	32.931
2001-10-01	32.097
2002-01-01	32.265
2002-04-01	37.389
2002-07-01	37.779
2002-10-01	38.241
2003-01-01	39.575
2003-04-01	43.493
2003-07-01	46.441
2003-10-01	52.599
2004-01-01	53.040
2004-04-01	50.517
2004-07-01	54.241
2004-10-01	57.502
2005-01-01	56.587
2005-04-01	58.733
2005-07-01	58.510
2005-10-01	59.818
2006-01-01	64.860
2006-04-01	69.317
2006-07-01	70.999
2006-10-01	74.361
2007-01-01	78.213
2007-04-01	83.151
2007-07-01	86.828
2007-10-01	92.311
2008-01-01	95.776
2008-04-01	98.274
2008-07-01	95.532
2008-10-01	92.624
2009-01-01	93.788
2009-04-01	101.558
2009-07-01	113.801
2009-10-01	119.837
2010-01-01	119.139
2010-04-01	114.601
2010-07-01	124.903
2010-10-01	126.371
2011-01-01	131.080
2011-04-01	138.024
2011-07-01	132.475
2011-10-01	127.952
2012-01-01	132.495
2012-04-01	133.409
2012-07-01	138.049
2012-10-01	147.288
2013-01-01	150.159
2013-04-01	150.017
2013-07-01	154.643
2013-10-01	151.548
2014-01-01	151.035
2014-04-01	147.453
2014-07-01	142.647
2014-10-01	139.669
2015-01-01	128.488
2015-04-01	136.048