Quarter	Billions of US Dollars
1987-01-01	1.148
1987-04-01	1.304
1987-07-01	1.327
1987-10-01	1.570
1988-01-01	1.764
1988-04-01	1.719
1988-07-01	1.708
1988-10-01	1.806
1989-01-01	1.740
1989-04-01	1.802
1989-07-01	1.973
1989-10-01	2.097
1990-01-01	2.169
1990-04-01	2.329
1990-07-01	2.470
1990-10-01	2.385
1991-01-01	2.300
1991-04-01	2.397
1991-07-01	2.544
1991-10-01	3.069
1992-01-01	2.920
1992-04-01	3.296
1992-07-01	3.484
1992-10-01	3.118
1993-01-01	2.922
1993-04-01	2.942
1993-07-01	3.091
1993-10-01	3.008
1994-01-01	2.959
1994-04-01	3.395
1994-07-01	3.724
1994-10-01	3.674
1995-01-01	4.032
1995-04-01	4.431
1995-07-01	4.694
1995-10-01	5.067
1996-01-01	5.147
1996-04-01	5.849
1996-07-01	5.932
1996-10-01	5.740
1997-01-01	5.335
1997-04-01	6.003
1997-07-01	5.801
1997-10-01	6.131
1998-01-01	6.191
1998-04-01	6.463
1998-07-01	6.605
1998-10-01	6.896
1999-01-01	6.660
1999-04-01	7.387
1999-07-01	8.028
1999-10-01	7.389
2000-01-01	7.017
2000-04-01	7.234
2000-07-01	6.547
2000-10-01	7.377
2001-01-01	7.133
2001-04-01	6.911
2001-07-01	7.245
2001-10-01	6.910
2002-01-01	6.468
2002-04-01	8.677
2002-07-01	8.764
2002-10-01	9.712
2003-01-01	9.710
2003-04-01	9.043
2003-07-01	9.249
2003-10-01	9.620
2004-01-01	9.747
2004-04-01	10.089
2004-07-01	11.394
2004-10-01	12.705
2005-01-01	12.072
2005-04-01	14.526
2005-07-01	14.466
2005-10-01	14.655
2006-01-01	15.852
2006-04-01	17.810
2006-07-01	17.758
2006-10-01	22.856
2007-01-01	24.397
2007-04-01	26.011
2007-07-01	31.056
2007-10-01	36.425
2008-01-01	39.136
2008-04-01	43.816
2008-07-01	39.731
2008-10-01	70.134
2009-01-01	74.056
2009-04-01	83.180
2009-07-01	87.051
2009-10-01	91.617
2010-01-01	85.166
2010-04-01	84.966
2010-07-01	102.193
2010-10-01	101.179
2011-01-01	107.289
2011-04-01	107.724
2011-07-01	100.159
2011-10-01	96.154
2012-01-01	98.685
2012-04-01	97.226
2012-07-01	104.675
2012-10-01	108.330
2013-01-01	105.805
2013-04-01	108.665
2013-07-01	114.208
2013-10-01	118.714
2014-01-01	116.854
2014-04-01	114.028
2014-07-01	106.299
2014-10-01	103.871
2015-01-01	94.249
2015-04-01	97.642