Quarter	Billions of US Dollars
1987-01-01	0.6166
1987-04-01	0.6155
1987-07-01	0.6100
1987-10-01	0.6426
1988-01-01	0.6968
1988-04-01	0.7434
1988-07-01	0.7320
1988-10-01	0.7512
1989-01-01	0.8045
1989-04-01	0.7171
1989-07-01	0.6300
1989-10-01	0.5880
1990-01-01	0.5923
1990-04-01	0.6015
1990-07-01	0.7977
1990-10-01	0.8179
1991-01-01	0.7463
1991-04-01	0.7215
1991-07-01	0.6630
1991-10-01	0.6125
1992-01-01	0.7219
1992-04-01	0.7581
1992-07-01	0.8028
1992-10-01	0.7354
1993-01-01	0.8412
1993-04-01	0.7215
1993-07-01	1.0492
1993-10-01	1.0663
1994-01-01	1.1284
1994-04-01	1.2340
1994-07-01	1.3475
1994-10-01	1.5406
1995-01-01	1.7637
1995-04-01	1.8672
1995-07-01	1.6962
1995-10-01	1.6843
1996-01-01	1.5985
1996-04-01	1.7477
1996-07-01	1.7462
1996-10-01	1.8315
1997-01-01	1.7746
1997-04-01	1.8501
1997-07-01	1.7391
1997-10-01	1.7730
1998-01-01	1.9288
1998-04-01	1.9517
1998-07-01	1.9436
1998-10-01	2.1860
1999-01-01	2.2302
1999-04-01	2.1215
1999-07-01	2.2764
1999-10-01	2.5781
2000-01-01	2.9263
2000-04-01	3.1481
2000-07-01	3.2493
2000-10-01	3.3243
2001-01-01	3.5371
2001-04-01	3.5152
2001-07-01	4.0559
2001-10-01	4.2483
2002-01-01	4.6575
2002-04-01	5.3069
2002-07-01	5.9526
2002-10-01	6.7697
2003-01-01	7.0651
2003-04-01	7.7378
2003-07-01	8.0719
2003-10-01	8.6102
2004-01-01	8.8787
2004-04-01	8.4968
2004-07-01	8.7063
2004-10-01	9.0983
2005-01-01	9.1712
2005-04-01	8.6269
2005-07-01	8.1939
2005-10-01	8.2276
2006-01-01	7.8781
2006-04-01	10.2595
2006-07-01	10.1025
2006-10-01	12.0234
2007-01-01	11.1781
2007-04-01	10.9904
2007-07-01	9.6323
2007-10-01	11.5878
2008-01-01	12.6700
2008-04-01	12.7306
2008-07-01	12.2687
2008-10-01	11.8928
2009-01-01	13.2987
2009-04-01	15.4575
2009-07-01	16.8640
2009-10-01	18.2892
2010-01-01	19.2762
2010-04-01	20.9715
2010-07-01	23.7109
2010-10-01	23.9872
2011-01-01	26.0418
2011-04-01	25.6630
2011-07-01	25.7582
2011-10-01	24.9514
2012-01-01	26.5919
2012-04-01	26.8618
2012-07-01	29.3992
2012-10-01	30.4877
2013-01-01	32.3915
2013-04-01	31.1884
2013-07-01	32.6207
2013-10-01	32.0772
2014-01-01	32.5818
2014-04-01	31.7508
2014-07-01	29.9474
2014-10-01	28.4598
2015-01-01	27.4703
2015-04-01	28.5256