Quarter	Billions of US Dollars
1987-01-01	2.958
1987-04-01	3.013
1987-07-01	2.909
1987-10-01	3.166
1988-01-01	2.748
1988-04-01	2.597
1988-07-01	2.644
1988-10-01	2.706
1989-01-01	2.487
1989-04-01	2.332
1989-07-01	2.364
1989-10-01	2.376
1990-01-01	2.472
1990-04-01	2.260
1990-07-01	2.158
1990-10-01	2.383
1991-01-01	2.833
1991-04-01	3.841
1991-07-01	3.982
1991-10-01	4.087
1992-01-01	4.526
1992-04-01	4.880
1992-07-01	5.288
1992-10-01	4.993
1993-01-01	5.626
1993-04-01	6.146
1993-07-01	6.383
1993-10-01	6.413
1994-01-01	6.829
1994-04-01	8.009
1994-07-01	8.647
1994-10-01	8.905
1995-01-01	10.979
1995-04-01	12.908
1995-07-01	13.699
1995-10-01	15.396
1996-01-01	16.610
1996-04-01	18.376
1996-07-01	22.617
1996-10-01	26.359
1997-01-01	27.479
1997-04-01	28.829
1997-07-01	30.524
1997-10-01	29.281
1998-01-01	28.308
1998-04-01	27.706
1998-07-01	27.188
1998-10-01	27.337
1999-01-01	26.300
1999-04-01	24.860
1999-07-01	23.861
1999-10-01	24.330
2000-01-01	25.147
2000-04-01	24.096
2000-07-01	23.000
2000-10-01	21.618
2001-01-01	20.506
2001-04-01	19.146
2001-07-01	17.096
2001-10-01	16.856
2002-01-01	14.490
2002-04-01	15.040
2002-07-01	15.440
2002-10-01	15.899
2003-01-01	17.013
2003-04-01	18.643
2003-07-01	21.106
2003-10-01	22.145
2004-01-01	26.096
2004-04-01	26.715
2004-07-01	27.392
2004-10-01	29.351
2005-01-01	31.391
2005-04-01	31.578
2005-07-01	32.367
2005-10-01	34.554
2006-01-01	35.448
2006-04-01	38.971
2006-07-01	41.508
2006-10-01	42.476
2007-01-01	44.195
2007-04-01	50.496
2007-07-01	52.623
2007-10-01	55.358
2008-01-01	58.798
2008-04-01	61.842
2008-07-01	59.142
2008-10-01	53.301
2009-01-01	55.236
2009-04-01	62.656
2009-07-01	65.935
2009-10-01	63.296
2010-01-01	64.854
2010-04-01	66.089
2010-07-01	71.122
2010-10-01	70.779
2011-01-01	74.249
2011-04-01	75.512
2011-07-01	78.359
2011-10-01	82.945
2012-01-01	87.901
2012-04-01	86.806
2012-07-01	93.809
2012-10-01	89.836
2013-01-01	90.595
2013-04-01	86.582
2013-07-01	95.452
2013-10-01	99.475
2014-01-01	100.722
2014-04-01	99.768
2014-07-01	96.571
2014-10-01	98.614
2015-01-01	96.986
2015-04-01	101.468