Quarter	Billions of US Dollars
1987-01-01	2.947
1987-04-01	3.332
1987-07-01	3.450
1987-10-01	4.075
1988-01-01	3.619
1988-04-01	4.121
1988-07-01	4.382
1988-10-01	5.050
1989-01-01	4.966
1989-04-01	4.950
1989-07-01	5.780
1989-10-01	4.984
1990-01-01	4.568
1990-04-01	5.078
1990-07-01	6.378
1990-10-01	6.571
1991-01-01	7.952
1991-04-01	10.041
1991-07-01	9.637
1991-10-01	9.259
1992-01-01	9.391
1992-04-01	9.762
1992-07-01	11.062
1992-10-01	9.243
1993-01-01	6.775
1993-04-01	7.086
1993-07-01	8.075
1993-10-01	7.749
1994-01-01	7.828
1994-04-01	7.120
1994-07-01	7.147
1994-10-01	6.202
1995-01-01	7.535
1995-04-01	6.189
1995-07-01	7.104
1995-10-01	7.632
1996-01-01	8.259
1996-04-01	14.215
1996-07-01	14.100
1996-10-01	12.328
1997-01-01	14.506
1997-04-01	12.272
1997-07-01	15.461
1997-10-01	15.631
1998-01-01	18.522
1998-04-01	15.688
1998-07-01	18.174
1998-10-01	17.814
1999-01-01	19.323
1999-04-01	16.757
1999-07-01	18.558
1999-10-01	19.122
2000-01-01	20.986
2000-04-01	20.889
2000-07-01	23.423
2000-10-01	25.402
2001-01-01	26.125
2001-04-01	24.523
2001-07-01	24.342
2001-10-01	22.201
2002-01-01	20.704
2002-04-01	23.485
2002-07-01	19.608
2002-10-01	24.871
2003-01-01	23.488
2003-04-01	25.882
2003-07-01	27.864
2003-10-01	31.801
2004-01-01	35.796
2004-04-01	40.624
2004-07-01	45.168
2004-10-01	48.440
2005-01-01	57.764
2005-04-01	55.043
2005-07-01	56.235
2005-10-01	52.852
2006-01-01	55.257
2006-04-01	52.269
2006-07-01	48.923
2006-10-01	57.141
2007-01-01	56.710
2007-04-01	74.027
2007-07-01	70.777
2007-10-01	79.568
2008-01-01	95.849
2008-04-01	119.434
2008-07-01	108.365
2008-10-01	95.233
2009-01-01	93.040
2009-04-01	85.919
2009-07-01	84.403
2009-10-01	80.607
2010-01-01	95.926
2010-04-01	100.732
2010-07-01	108.152
2010-10-01	102.204
2011-01-01	135.798
2011-04-01	133.276
2011-07-01	105.923
2011-10-01	93.916
2012-01-01	99.671
2012-04-01	79.514
2012-07-01	96.592
2012-10-01	88.979
2013-01-01	93.712
2013-04-01	95.466
2013-07-01	97.381
2013-10-01	88.121
2014-01-01	101.024
2014-04-01	98.225
2014-07-01	98.875
2014-10-01	87.059
2015-01-01	81.388
2015-04-01	78.231