Quarter	Billions of US Dollars
1987-01-01	6.623
1987-04-01	6.748
1987-07-01	7.325
1987-10-01	7.315
1988-01-01	6.968
1988-04-01	7.467
1988-07-01	7.643
1988-10-01	7.340
1989-01-01	7.709
1989-04-01	7.412
1989-07-01	7.338
1989-10-01	7.250
1990-01-01	6.832
1990-04-01	6.682
1990-07-01	6.856
1990-10-01	6.630
1991-01-01	5.834
1991-04-01	5.448
1991-07-01	5.369
1991-10-01	5.159
1992-01-01	4.422
1992-04-01	4.323
1992-07-01	4.433
1992-10-01	3.707
1993-01-01	3.322
1993-04-01	2.703
1993-07-01	2.524
1993-10-01	2.329
1994-01-01	2.124
1994-04-01	1.912
1994-07-01	1.862
1994-10-01	1.531
1995-01-01	1.514
1995-04-01	1.492
1995-07-01	1.465
1995-10-01	1.415
1996-01-01	1.721
1996-04-01	1.612
1996-07-01	1.722
1996-10-01	2.480
1997-01-01	2.611
1997-04-01	2.800
1997-07-01	5.063
1997-10-01	5.766
1998-01-01	6.304
1998-04-01	8.639
1998-07-01	9.142
1998-10-01	8.863
1999-01-01	8.703
1999-04-01	9.813
1999-07-01	10.325
1999-10-01	9.699
2000-01-01	10.831
2000-04-01	12.092
2000-07-01	12.314
2000-10-01	13.238
2001-01-01	14.948
2001-04-01	15.023
2001-07-01	16.277
2001-10-01	16.739
2002-01-01	17.478
2002-04-01	19.221
2002-07-01	18.863
2002-10-01	19.874
2003-01-01	22.384
2003-04-01	24.271
2003-07-01	27.352
2003-10-01	30.718
2004-01-01	31.324
2004-04-01	32.038
2004-07-01	33.174
2004-10-01	39.863
2005-01-01	40.587
2005-04-01	40.246
2005-07-01	39.894
2005-10-01	42.789
2006-01-01	46.599
2006-04-01	55.661
2006-07-01	59.510
2006-10-01	67.430
2007-01-01	73.736
2007-04-01	74.013
2007-07-01	79.258
2007-10-01	90.779
2008-01-01	108.208
2008-04-01	116.949
2008-07-01	109.236
2008-10-01	108.941
2009-01-01	106.925
2009-04-01	113.379
2009-07-01	121.810
2009-10-01	118.634
2010-01-01	123.891
2010-04-01	122.984
2010-07-01	138.570
2010-10-01	135.627
2011-01-01	158.666
2011-04-01	164.444
2011-07-01	160.158
2011-10-01	170.195
2012-01-01	193.402
2012-04-01	197.095
2012-07-01	205.479
2012-10-01	200.942
2013-01-01	197.973
2013-04-01	205.649
2013-07-01	208.948
2013-10-01	215.850
2014-01-01	218.632
2014-04-01	212.432
2014-07-01	201.364
2014-10-01	198.300
2015-01-01	188.057
2015-04-01	184.100