Quarter	Billions of US Dollars
1987-01-01	5.172
1987-04-01	4.888
1987-07-01	5.088
1987-10-01	5.283
1988-01-01	5.471
1988-04-01	5.289
1988-07-01	4.631
1988-10-01	4.838
1989-01-01	4.626
1989-04-01	4.332
1989-07-01	4.549
1989-10-01	4.873
1990-01-01	5.160
1990-04-01	5.706
1990-07-01	6.430
1990-10-01	6.420
1991-01-01	6.405
1991-04-01	6.587
1991-07-01	6.766
1991-10-01	7.356
1992-01-01	7.271
1992-04-01	8.310
1992-07-01	9.760
1992-10-01	9.479
1993-01-01	9.594
1993-04-01	10.956
1993-07-01	12.322
1993-10-01	12.996
1994-01-01	14.394
1994-04-01	15.984
1994-07-01	15.980
1994-10-01	15.782
1995-01-01	17.043
1995-04-01	16.503
1995-07-01	15.770
1995-10-01	15.991
1996-01-01	15.584
1996-04-01	18.793
1996-07-01	19.937
1996-10-01	20.886
1997-01-01	20.967
1997-04-01	21.306
1997-07-01	21.486
1997-10-01	25.567
1998-01-01	32.294
1998-04-01	33.257
1998-07-01	39.853
1998-10-01	43.216
1999-01-01	42.209
1999-04-01	43.472
1999-07-01	44.254
1999-10-01	46.499
2000-01-01	47.656
2000-04-01	48.756
2000-07-01	49.012
2000-10-01	58.095
2001-01-01	57.357
2001-04-01	60.223
2001-07-01	67.371
2001-10-01	71.597
2002-01-01	75.325
2002-04-01	92.346
2002-07-01	95.442
2002-10-01	104.091
2003-01-01	113.067
2003-04-01	135.577
2003-07-01	145.771
2003-10-01	161.050
2004-01-01	162.908
2004-04-01	172.183
2004-07-01	183.171
2004-10-01	217.442
2005-01-01	218.828
2005-04-01	215.242
2005-07-01	215.529
2005-10-01	213.953
2006-01-01	225.460
2006-04-01	234.790
2006-07-01	233.375
2006-10-01	258.391
2007-01-01	261.117
2007-04-01	270.862
2007-07-01	284.230
2007-10-01	305.892
2008-01-01	319.016
2008-04-01	322.121
2008-07-01	306.415
2008-10-01	329.415
2009-01-01	351.637
2009-04-01	434.000
2009-07-01	444.121
2009-10-01	459.132
2010-01-01	447.718
2010-04-01	434.364
2010-07-01	480.012
2010-10-01	483.623
2011-01-01	526.878
2011-04-01	531.504
2011-07-01	514.675
2011-10-01	508.061
2012-01-01	537.592
2012-04-01	492.808
2012-07-01	513.560
2012-10-01	505.939
2013-01-01	487.968
2013-04-01	495.590
2013-07-01	499.124
2013-10-01	497.021
2014-01-01	508.747
2014-04-01	490.205
2014-07-01	464.854
2014-10-01	448.973
2015-01-01	423.838
2015-04-01	430.741