Quarter	Billions of US Dollars
1987-01-01	2.327
1987-04-01	2.470
1987-07-01	2.599
1987-10-01	2.811
1988-01-01	2.672
1988-04-01	2.944
1988-07-01	2.916
1988-10-01	3.715
1989-01-01	3.790
1989-04-01	3.557
1989-07-01	3.805
1989-10-01	3.928
1990-01-01	4.322
1990-04-01	4.045
1990-07-01	4.572
1990-10-01	5.282
1991-01-01	5.336
1991-04-01	6.903
1991-07-01	8.143
1991-10-01	8.473
1992-01-01	8.903
1992-04-01	9.124
1992-07-01	9.247
1992-10-01	9.070
1993-01-01	9.537
1993-04-01	10.568
1993-07-01	11.259
1993-10-01	11.251
1994-01-01	12.279
1994-04-01	12.076
1994-07-01	12.913
1994-10-01	14.446
1995-01-01	15.693
1995-04-01	16.040
1995-07-01	16.683
1995-10-01	16.588
1996-01-01	16.583
1996-04-01	16.675
1996-07-01	16.022
1996-10-01	14.959
1997-01-01	15.723
1997-04-01	16.994
1997-07-01	19.529
1997-10-01	23.141
1998-01-01	23.298
1998-04-01	25.191
1998-07-01	27.256
1998-10-01	26.934
1999-01-01	27.953
1999-04-01	28.609
1999-07-01	30.921
1999-10-01	30.248
2000-01-01	30.098
2000-04-01	33.156
2000-07-01	31.366
2000-10-01	38.367
2001-01-01	38.121
2001-04-01	42.925
2001-07-01	47.135
2001-10-01	48.522
2002-01-01	48.776
2002-04-01	55.301
2002-07-01	54.735
2002-10-01	57.935
2003-01-01	59.915
2003-04-01	61.177
2003-07-01	64.992
2003-10-01	72.736
2004-01-01	71.518
2004-04-01	73.316
2004-07-01	76.101
2004-10-01	79.595
2005-01-01	75.754
2005-04-01	72.562
2005-07-01	74.479
2005-10-01	72.147
2006-01-01	74.612
2006-04-01	87.653
2006-07-01	86.762
2006-10-01	95.406
2007-01-01	96.469
2007-04-01	108.659
2007-07-01	117.037
2007-10-01	121.362
2008-01-01	129.401
2008-04-01	136.363
2008-07-01	126.320
2008-10-01	120.970
2009-01-01	146.663
2009-04-01	165.670
2009-07-01	168.431
2009-10-01	164.992
2010-01-01	158.701
2010-04-01	149.370
2010-07-01	160.804
2010-10-01	154.452
2011-01-01	162.245
2011-04-01	163.352
2011-07-01	155.555
2011-10-01	152.435
2012-01-01	157.874
2012-04-01	153.318
2012-07-01	159.749
2012-10-01	172.025
2013-01-01	157.889
2013-04-01	155.949
2013-07-01	158.959
2013-10-01	157.359
2014-01-01	156.661
2014-04-01	162.464
2014-07-01	152.090
2014-10-01	142.059
2015-01-01	142.146
2015-04-01	147.977