Quarter	Billions of US Dollars
1987-01-01	0.2967
1987-04-01	0.2935
1987-07-01	0.3900
1987-10-01	0.4629
1988-01-01	0.4347
1988-04-01	0.3947
1988-07-01	0.4713
1988-10-01	0.5822
1989-01-01	0.5343
1989-04-01	0.5259
1989-07-01	0.5458
1989-10-01	0.5812
1990-01-01	0.7712
1990-04-01	0.9391
1990-07-01	1.0160
1990-10-01	1.4345
1991-01-01	1.4390
1991-04-01	1.3661
1991-07-01	1.5140
1991-10-01	2.0349
1992-01-01	2.0826
1992-04-01	2.4176
1992-07-01	2.6623
1992-10-01	2.5659
1993-01-01	2.8049
1993-04-01	2.9827
1993-07-01	3.0479
1993-10-01	3.4192
1994-01-01	3.5030
1994-04-01	3.7373
1994-07-01	3.7887
1994-10-01	3.9192
1995-01-01	4.6043
1995-04-01	4.3986
1995-07-01	4.6681
1995-10-01	5.2493
1996-01-01	4.9673
1996-04-01	5.0666
1996-07-01	5.1264
1996-10-01	5.1124
1997-01-01	5.0772
1997-04-01	5.0529
1997-07-01	5.1710
1997-10-01	4.9935
1998-01-01	4.8372
1998-04-01	4.8965
1998-07-01	5.1997
1998-10-01	5.2325
1999-01-01	4.9318
1999-04-01	4.9444
1999-07-01	4.9927
1999-10-01	4.8397
2000-01-01	4.4530
2000-04-01	4.3682
2000-07-01	4.2501
2000-10-01	4.7126
2001-01-01	4.5234
2001-04-01	4.5042
2001-07-01	5.2661
2001-10-01	7.2092
2002-01-01	7.0916
2002-04-01	8.9931
2002-07-01	9.0332
2002-10-01	9.8070
2003-01-01	9.9662
2003-04-01	10.9361
2003-07-01	12.3825
2003-10-01	14.3835
2004-01-01	14.5839
2004-04-01	15.7573
2004-07-01	16.8662
2004-10-01	20.1089
2005-01-01	19.3625
2005-04-01	19.5214
2005-07-01	19.2738
2005-10-01	19.2753
2006-01-01	21.4996
2006-04-01	22.2693
2006-07-01	24.7461
2006-10-01	27.8454
2007-01-01	33.4787
2007-04-01	34.1028
2007-07-01	35.6408
2007-10-01	35.2183
2008-01-01	37.8421
2008-04-01	37.7504
2008-07-01	34.4628
2008-10-01	34.7146
2009-01-01	34.0111
2009-04-01	35.3125
2009-07-01	37.3742
2009-10-01	36.6756
2010-01-01	34.6546
2010-04-01	32.0504
2010-07-01	35.1578
2010-10-01	33.8400
2011-01-01	34.9369
2011-04-01	35.5562
2011-07-01	32.5166
2011-10-01	30.2404
2012-01-01	32.3929
2012-04-01	30.5827
2012-07-01	29.4724
2012-10-01	30.2278
2013-01-01	28.6917
2013-04-01	29.1520
2013-07-01	30.5662
2013-10-01	31.6753
2014-01-01	30.1423
2014-04-01	29.7411
2014-07-01	28.2108
2014-10-01	26.3362
2015-01-01	23.6386
2015-04-01	23.4960