Quarter	Billions of US Dollars
1987-01-01	0.013
1987-04-01	0.013
1987-07-01	0.039
1987-10-01	0.046
1988-01-01	0.074
1988-04-01	0.067
1988-07-01	0.065
1988-10-01	0.068
1989-01-01	0.064
1989-04-01	0.057
1989-07-01	0.447
1989-10-01	0.446
1990-01-01	0.459
1990-04-01	0.479
1990-07-01	0.520
1990-10-01	0.536
1991-01-01	0.460
1991-04-01	0.445
1991-07-01	0.515
1991-10-01	0.550
1992-01-01	0.774
1992-04-01	0.838
1992-07-01	0.819
1992-10-01	1.157
1993-01-01	1.168
1993-04-01	1.298
1993-07-01	1.666
1993-10-01	1.816
1994-01-01	1.812
1994-04-01	1.820
1994-07-01	1.738
1994-10-01	1.692
1995-01-01	1.910
1995-04-01	2.163
1995-07-01	2.226
1995-10-01	3.319
1996-01-01	7.288
1996-04-01	7.532
1996-07-01	7.822
1996-10-01	8.580
1997-01-01	8.974
1997-04-01	9.515
1997-07-01	9.859
1997-10-01	9.873
1998-01-01	11.023
1998-04-01	11.425
1998-07-01	12.974
1998-10-01	12.586
1999-01-01	13.690
1999-04-01	14.630
1999-07-01	16.415
1999-10-01	17.152
2000-01-01	17.387
2000-04-01	19.146
2000-07-01	18.983
2000-10-01	19.323
2001-01-01	21.953
2001-04-01	22.642
2001-07-01	24.224
2001-10-01	23.760
2002-01-01	24.778
2002-04-01	26.833
2002-07-01	29.164
2002-10-01	34.515
2003-01-01	36.662
2003-04-01	41.272
2003-07-01	46.087
2003-10-01	51.525
2004-01-01	54.929
2004-04-01	55.996
2004-07-01	61.917
2004-10-01	72.864
2005-01-01	74.383
2005-04-01	76.829
2005-07-01	82.331
2005-10-01	86.791
2006-01-01	93.074
2006-04-01	106.823
2006-07-01	119.425
2006-10-01	131.613
2007-01-01	163.694
2007-04-01	187.182
2007-07-01	221.276
2007-10-01	235.912
2008-01-01	255.619
2008-04-01	291.071
2008-07-01	267.872
2008-10-01	287.181
2009-01-01	299.477
2009-04-01	320.671
2009-07-01	341.380
2009-10-01	339.989
2010-01-01	316.029
2010-04-01	299.259
2010-07-01	321.691
2010-10-01	334.954
2011-01-01	317.497
2011-04-01	316.207
2011-07-01	295.870
2011-10-01	286.217
2012-01-01	332.131
2012-04-01	322.094
2012-07-01	329.905
2012-10-01	336.367
2013-01-01	327.285
2013-04-01	326.244
2013-07-01	340.419
2013-10-01	352.892
2014-01-01	315.067
2014-04-01	308.546
2014-07-01	286.459
2014-10-01	252.101
2015-01-01	204.683
2015-04-01	225.375