Quarter	Billions of US Dollars
1987-01-01	3.017
1987-04-01	3.331
1987-07-01	4.001
1987-10-01	4.270
1988-01-01	4.884
1988-04-01	4.350
1988-07-01	5.536
1988-10-01	5.301
1989-01-01	5.377
1989-04-01	5.347
1989-07-01	5.127
1989-10-01	4.545
1990-01-01	5.875
1990-04-01	5.710
1990-07-01	6.933
1990-10-01	6.514
1991-01-01	6.890
1991-04-01	6.891
1991-07-01	6.556
1991-10-01	7.031
1992-01-01	7.469
1992-04-01	7.505
1992-07-01	7.671
1992-10-01	6.384
1993-01-01	6.242
1993-04-01	6.235
1993-07-01	2.700
1993-10-01	2.797
1994-01-01	3.596
1994-04-01	3.609
1994-07-01	3.515
1994-10-01	2.145
1995-01-01	1.985
1995-04-01	2.385
1995-07-01	2.534
1995-10-01	2.614
1996-01-01	3.829
1996-04-01	4.515
1996-07-01	4.208
1996-10-01	4.204
1997-01-01	4.600
1997-04-01	6.325
1997-07-01	9.437
1997-10-01	10.102
1998-01-01	10.070
1998-04-01	10.969
1998-07-01	13.510
1998-10-01	17.160
1999-01-01	18.672
1999-04-01	21.125
1999-07-01	25.430
1999-10-01	25.320
2000-01-01	23.358
2000-04-01	27.885
2000-07-01	29.868
2000-10-01	31.938
2001-01-01	36.523
2001-04-01	34.252
2001-07-01	35.463
2001-10-01	35.644
2002-01-01	31.993
2002-04-01	36.941
2002-07-01	36.399
2002-10-01	40.273
2003-01-01	43.079
2003-04-01	42.608
2003-07-01	40.627
2003-10-01	45.712
2004-01-01	43.579
2004-04-01	49.352
2004-07-01	45.346
2004-10-01	45.924
2005-01-01	48.959
2005-04-01	46.366
2005-07-01	47.333
2005-10-01	49.322
2006-01-01	54.677
2006-04-01	64.912
2006-07-01	64.083
2006-10-01	64.641
2007-01-01	71.632
2007-04-01	75.410
2007-07-01	72.878
2007-10-01	66.365
2008-01-01	91.159
2008-04-01	84.203
2008-07-01	90.978
2008-10-01	85.702
2009-01-01	86.351
2009-04-01	85.596
2009-07-01	100.447
2009-10-01	86.607
2010-01-01	85.790
2010-04-01	68.339
2010-07-01	92.131
2010-10-01	91.660
2011-01-01	95.257
2011-04-01	100.881
2011-07-01	102.920
2011-10-01	103.770
2012-01-01	121.194
2012-04-01	112.381
2012-07-01	111.896
2012-10-01	110.348
2013-01-01	99.289
2013-04-01	105.892
2013-07-01	101.587
2013-10-01	84.832
2014-01-01	82.209
2014-04-01	87.974
2014-07-01	74.765
2014-10-01	66.718
2015-01-01	66.984
2015-04-01	63.662