Quarter	Billions of US Dollars
1987-01-01	0.401
1987-04-01	0.436
1987-07-01	0.544
1987-10-01	0.374
1988-01-01	0.565
1988-04-01	0.412
1988-07-01	0.348
1988-10-01	0.617
1989-01-01	0.725
1989-04-01	0.363
1989-07-01	0.590
1989-10-01	0.404
1990-01-01	0.369
1990-04-01	0.221
1990-07-01	0.318
1990-10-01	0.401
1991-01-01	0.190
1991-04-01	0.882
1991-07-01	1.089
1991-10-01	1.525
1992-01-01	1.886
1992-04-01	2.306
1992-07-01	2.414
1992-10-01	4.242
1993-01-01	3.029
1993-04-01	4.199
1993-07-01	3.279
1993-10-01	4.666
1994-01-01	5.042
1994-04-01	6.201
1994-07-01	6.642
1994-10-01	6.702
1995-01-01	8.326
1995-04-01	8.850
1995-07-01	8.827
1995-10-01	10.378
1996-01-01	11.301
1996-04-01	13.314
1996-07-01	15.534
1996-10-01	17.247
1997-01-01	19.670
1997-04-01	21.084
1997-07-01	21.842
1997-10-01	22.672
1998-01-01	25.557
1998-04-01	23.051
1998-07-01	25.091
1998-10-01	27.636
1999-01-01	36.696
1999-04-01	40.173
1999-07-01	54.746
1999-10-01	71.728
2000-01-01	82.367
2000-04-01	106.850
2000-07-01	112.675
2000-10-01	125.714
2001-01-01	117.284
2001-04-01	105.633
2001-07-01	96.241
2001-10-01	89.454
2002-01-01	86.298
2002-04-01	91.720
2002-07-01	98.120
2002-10-01	96.823
2003-01-01	122.464
2003-04-01	116.029
2003-07-01	99.666
2003-10-01	121.245
2004-01-01	117.630
2004-04-01	119.774
2004-07-01	118.348
2004-10-01	125.930
2005-01-01	122.576
2005-04-01	113.523
2005-07-01	100.177
2005-10-01	96.862
2006-01-01	108.640
2006-04-01	117.028
2006-07-01	114.569
2006-10-01	114.417
2007-01-01	128.610
2007-04-01	156.214
2007-07-01	170.537
2007-10-01	192.268
2008-01-01	202.053
2008-04-01	208.035
2008-07-01	184.389
2008-10-01	142.374
2009-01-01	120.664
2009-04-01	114.109
2009-07-01	110.610
2009-10-01	96.283
2010-01-01	102.505
2010-04-01	98.548
2010-07-01	104.369
2010-10-01	103.908
2011-01-01	120.806
2011-04-01	128.253
2011-07-01	160.967
2011-10-01	164.385
2012-01-01	165.398
2012-04-01	173.739
2012-07-01	147.161
2012-10-01	140.947
2013-01-01	151.131
2013-04-01	164.280
2013-07-01	163.933
2013-10-01	140.415
2014-01-01	152.361
2014-04-01	159.114
2014-07-01	162.514
2014-10-01	156.584
2015-01-01	170.758
2015-04-01	163.634