Quarter	Billions of US Dollars
1987-01-01	0.8590
1987-04-01	0.7390
1987-07-01	0.8790
1987-10-01	0.8530
1988-01-01	0.7750
1988-04-01	0.6690
1988-07-01	0.9670
1988-10-01	0.9700
1989-01-01	1.3660
1989-04-01	1.1640
1989-07-01	1.3270
1989-10-01	1.0460
1990-01-01	1.4860
1990-04-01	1.6740
1990-07-01	1.8140
1990-10-01	1.2500
1991-01-01	1.6280
1991-04-01	1.6230
1991-07-01	1.3690
1991-10-01	1.3410
1992-01-01	1.5230
1992-04-01	1.6430
1992-07-01	2.0100
1992-10-01	1.6010
1993-01-01	1.5060
1993-04-01	1.1630
1993-07-01	0.9790
1993-10-01	1.1094
1994-01-01	0.8493
1994-04-01	1.0294
1994-07-01	1.4111
1994-10-01	1.1584
1995-01-01	1.1498
1995-04-01	0.9495
1995-07-01	1.3142
1995-10-01	1.5975
1996-01-01	2.0071
1996-04-01	1.4694
1996-07-01	1.1085
1996-10-01	1.6228
1997-01-01	2.1106
1997-04-01	1.7826
1997-07-01	1.8042
1997-10-01	2.1303
1998-01-01	1.3437
1998-04-01	1.6068
1998-07-01	1.3076
1998-10-01	1.0596
1999-01-01	1.7177
1999-04-01	2.0766
1999-07-01	3.7828
1999-10-01	4.2688
2000-01-01	6.8863
2000-04-01	7.2438
2000-07-01	8.7268
2000-10-01	6.7141
2001-01-01	9.7376
2001-04-01	8.0549
2001-07-01	6.6058
2001-10-01	6.7696
2002-01-01	6.5288
2002-04-01	7.4160
2002-07-01	6.4002
2002-10-01	4.6205
2003-01-01	8.1805
2003-04-01	6.5114
2003-07-01	4.3039
2003-10-01	3.9453
2004-01-01	5.4635
2004-04-01	5.8905
2004-07-01	7.2288
2004-10-01	5.7709
2005-01-01	8.0462
2005-04-01	9.1555
2005-07-01	7.9714
2005-10-01	7.7180
2006-01-01	14.3148
2006-04-01	18.5716
2006-07-01	14.0651
2006-10-01	10.7638
2007-01-01	18.3410
2007-04-01	27.9431
2007-07-01	33.3042
2007-10-01	16.1998
2008-01-01	22.9502
2008-04-01	22.3343
2008-07-01	22.4470
2008-10-01	28.5909
2009-01-01	28.0042
2009-04-01	21.8134
2009-07-01	18.2197
2009-10-01	14.9109
2010-01-01	17.0516
2010-04-01	14.6749
2010-07-01	16.6893
2010-10-01	14.4283
2011-01-01	26.6893
2011-04-01	21.0237
2011-07-01	21.9202
2011-10-01	18.0316
2012-01-01	17.6896
2012-04-01	15.1620
2012-07-01	14.8916
2012-10-01	16.6771
2013-01-01	18.1704
2013-04-01	12.5619
2013-07-01	17.7505
2013-10-01	18.7163
2014-01-01	20.7109
2014-04-01	20.9859
2014-07-01	18.3295
2014-10-01	17.2555
2015-01-01	16.8127
2015-04-01	13.9291