Quarter	Billions of US Dollars
1987-01-01	2.912
1987-04-01	3.030
1987-07-01	3.151
1987-10-01	3.455
1988-01-01	3.493
1988-04-01	3.184
1988-07-01	3.293
1988-10-01	3.903
1989-01-01	3.929
1989-04-01	4.469
1989-07-01	4.898
1989-10-01	5.656
1990-01-01	6.824
1990-04-01	7.144
1990-07-01	7.105
1990-10-01	7.396
1991-01-01	7.435
1991-04-01	7.090
1991-07-01	7.869
1991-10-01	8.228
1992-01-01	8.164
1992-04-01	8.579
1992-07-01	9.151
1992-10-01	8.247
1993-01-01	8.000
1993-04-01	7.739
1993-07-01	9.437
1993-10-01	8.912
1994-01-01	8.916
1994-04-01	9.127
1994-07-01	9.411
1994-10-01	9.317
1995-01-01	10.335
1995-04-01	10.616
1995-07-01	11.190
1995-10-01	11.216
1996-01-01	12.223
1996-04-01	12.888
1996-07-01	13.097
1996-10-01	13.873
1997-01-01	15.530
1997-04-01	18.260
1997-07-01	24.326
1997-10-01	25.838
1998-01-01	27.868
1998-04-01	31.329
1998-07-01	36.747
1998-10-01	36.729
1999-01-01	36.733
1999-04-01	39.277
1999-07-01	46.751
1999-10-01	50.567
2000-01-01	48.255
2000-04-01	48.869
2000-07-01	53.453
2000-10-01	74.007
2001-01-01	78.746
2001-04-01	81.804
2001-07-01	88.993
2001-10-01	98.927
2002-01-01	101.885
2002-04-01	118.457
2002-07-01	129.961
2002-10-01	143.751
2003-01-01	151.432
2003-04-01	166.514
2003-07-01	175.823
2003-10-01	200.998
2004-01-01	200.384
2004-04-01	211.896
2004-07-01	215.877
2004-10-01	241.208
2005-01-01	239.878
2005-04-01	237.669
2005-07-01	247.149
2005-10-01	279.443
2006-01-01	296.992
2006-04-01	331.112
2006-07-01	347.053
2006-10-01	390.292
2007-01-01	420.604
2007-04-01	444.624
2007-07-01	460.735
2007-10-01	469.292
2008-01-01	503.473
2008-04-01	538.399
2008-07-01	501.716
2008-10-01	507.040
2009-01-01	515.500
2009-04-01	560.661
2009-07-01	584.982
2009-10-01	573.277
2010-01-01	562.707
2010-04-01	523.499
2010-07-01	590.854
2010-10-01	577.822
2011-01-01	607.177
2011-04-01	623.407
2011-07-01	590.942
2011-10-01	597.824
2012-01-01	612.415
2012-04-01	584.235
2012-07-01	593.003
2012-10-01	609.644
2013-01-01	592.409
2013-04-01	597.981
2013-07-01	616.198
2013-10-01	604.322
2014-01-01	628.194
2014-04-01	634.249
2014-07-01	594.800
2014-10-01	586.833
2015-01-01	529.338
2015-04-01	560.928