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	0.060
1989-10-01	0.136
1990-01-01	0.249
1990-04-01	0.253
1990-07-01	0.484
1990-10-01	0.644
1991-01-01	0.618
1991-04-01	0.833
1991-07-01	0.908
1991-10-01	1.010
1992-01-01	1.199
1992-04-01	1.260
1992-07-01	1.388
1992-10-01	1.731
1993-01-01	1.729
1993-04-01	1.713
1993-07-01	2.595
1993-10-01	2.752
1994-01-01	2.707
1994-04-01	2.823
1994-07-01	3.125
1994-10-01	3.280
1995-01-01	3.604
1995-04-01	4.008
1995-07-01	4.445
1995-10-01	6.694
1996-01-01	9.121
1996-04-01	10.258
1996-07-01	10.646
1996-10-01	11.947
1997-01-01	13.730
1997-04-01	16.069
1997-07-01	17.557
1997-10-01	18.928
1998-01-01	20.842
1998-04-01	22.188
1998-07-01	25.850
1998-10-01	24.656
1999-01-01	25.980
1999-04-01	27.564
1999-07-01	30.325
1999-10-01	32.803
2000-01-01	31.532
2000-04-01	34.255
2000-07-01	34.094
2000-10-01	34.510
2001-01-01	36.774
2001-04-01	39.911
2001-07-01	41.037
2001-10-01	43.819
2002-01-01	45.210
2002-04-01	52.140
2002-07-01	56.197
2002-10-01	66.084
2003-01-01	71.100
2003-04-01	77.865
2003-07-01	88.168
2003-10-01	120.732
2004-01-01	126.936
2004-04-01	136.627
2004-07-01	156.833
2004-10-01	206.259
2005-01-01	215.304
2005-04-01	232.030
2005-07-01	239.991
2005-10-01	273.247
2006-01-01	310.901
2006-04-01	370.325
2006-07-01	433.049
2006-10-01	506.128
2007-01-01	564.946
2007-04-01	653.311
2007-07-01	721.157
2007-10-01	775.766
2008-01-01	834.336
2008-04-01	878.415
2008-07-01	822.159
2008-10-01	850.203
2009-01-01	863.475
2009-04-01	936.149
2009-07-01	991.689
2009-10-01	973.128
2010-01-01	905.692
2010-04-01	848.477
2010-07-01	927.081
2010-10-01	913.739
2011-01-01	892.297
2011-04-01	889.464
2011-07-01	832.488
2011-10-01	809.646
2012-01-01	870.165
2012-04-01	822.702
2012-07-01	834.277
2012-10-01	846.867
2013-01-01	818.418
2013-04-01	820.856
2013-07-01	838.027
2013-10-01	850.176
2014-01-01	812.581
2014-04-01	805.973
2014-07-01	740.910
2014-10-01	677.738
2015-01-01	595.687
2015-04-01	645.720