Quarter	Billions of US Dollars
1987-01-01	8.324
1987-04-01	8.465
1987-07-01	9.117
1987-10-01	9.228
1988-01-01	8.862
1988-04-01	9.400
1988-07-01	9.555
1988-10-01	9.324
1989-01-01	9.803
1989-04-01	9.517
1989-07-01	9.409
1989-10-01	9.643
1990-01-01	8.921
1990-04-01	8.916
1990-07-01	9.199
1990-10-01	9.011
1991-01-01	8.022
1991-04-01	7.641
1991-07-01	7.625
1991-10-01	7.510
1992-01-01	6.035
1992-04-01	5.964
1992-07-01	6.094
1992-10-01	5.315
1993-01-01	4.782
1993-04-01	3.805
1993-07-01	3.594
1993-10-01	3.341
1994-01-01	3.150
1994-04-01	2.855
1994-07-01	2.721
1994-10-01	2.406
1995-01-01	2.364
1995-04-01	2.268
1995-07-01	2.242
1995-10-01	2.292
1996-01-01	2.748
1996-04-01	2.739
1996-07-01	2.849
1996-10-01	3.607
1997-01-01	3.806
1997-04-01	3.994
1997-07-01	6.399
1997-10-01	6.899
1998-01-01	7.443
1998-04-01	10.071
1998-07-01	11.015
1998-10-01	10.622
1999-01-01	11.057
1999-04-01	11.820
1999-07-01	12.494
1999-10-01	11.912
2000-01-01	12.837
2000-04-01	14.204
2000-07-01	14.547
2000-10-01	15.698
2001-01-01	17.181
2001-04-01	17.249
2001-07-01	18.064
2001-10-01	18.929
2002-01-01	18.999
2002-04-01	20.508
2002-07-01	20.266
2002-10-01	21.290
2003-01-01	24.626
2003-04-01	26.450
2003-07-01	29.559
2003-10-01	33.049
2004-01-01	33.610
2004-04-01	34.262
2004-07-01	34.641
2004-10-01	41.392
2005-01-01	41.404
2005-04-01	41.656
2005-07-01	41.286
2005-10-01	44.001
2006-01-01	47.936
2006-04-01	56.739
2006-07-01	60.866
2006-10-01	67.781
2007-01-01	73.980
2007-04-01	74.370
2007-07-01	79.771
2007-10-01	91.144
2008-01-01	108.637
2008-04-01	117.604
2008-07-01	109.918
2008-10-01	109.153
2009-01-01	107.601
2009-04-01	113.978
2009-07-01	122.385
2009-10-01	119.286
2010-01-01	121.311
2010-04-01	122.391
2010-07-01	136.678
2010-10-01	135.995
2011-01-01	159.118
2011-04-01	167.386
2011-07-01	166.034
2011-10-01	172.787
2012-01-01	196.656
2012-04-01	201.455
2012-07-01	207.413
2012-10-01	204.478
2013-01-01	201.499
2013-04-01	209.094
2013-07-01	212.372
2013-10-01	218.758
2014-01-01	221.588
2014-04-01	214.416
2014-07-01	203.845
2014-10-01	200.787
2015-01-01	190.453
2015-04-01	187.777