Quarter	Billions of US Dollars
1987-01-01	3.844
1987-04-01	4.029
1987-07-01	3.995
1987-10-01	4.007
1988-01-01	3.888
1988-04-01	3.778
1988-07-01	3.815
1988-10-01	3.989
1989-01-01	4.031
1989-04-01	3.909
1989-07-01	3.603
1989-10-01	3.591
1990-01-01	3.517
1990-04-01	3.563
1990-07-01	3.558
1990-10-01	3.242
1991-01-01	3.173
1991-04-01	3.151
1991-07-01	3.313
1991-10-01	3.341
1992-01-01	3.092
1992-04-01	3.266
1992-07-01	3.544
1992-10-01	3.989
1993-01-01	3.902
1993-04-01	3.762
1993-07-01	5.769
1993-10-01	5.713
1994-01-01	6.688
1994-04-01	6.950
1994-07-01	7.498
1994-10-01	7.975
1995-01-01	9.113
1995-04-01	10.408
1995-07-01	11.418
1995-10-01	11.678
1996-01-01	13.535
1996-04-01	17.094
1996-07-01	18.822
1996-10-01	19.723
1997-01-01	22.201
1997-04-01	27.272
1997-07-01	29.954
1997-10-01	30.819
1998-01-01	32.742
1998-04-01	36.537
1998-07-01	39.426
1998-10-01	39.744
1999-01-01	38.693
1999-04-01	38.214
1999-07-01	41.149
1999-10-01	39.419
2000-01-01	38.121
2000-04-01	41.763
2000-07-01	42.061
2000-10-01	46.659
2001-01-01	45.066
2001-04-01	42.825
2001-07-01	40.636
2001-10-01	40.285
2002-01-01	40.077
2002-04-01	48.851
2002-07-01	48.037
2002-10-01	50.165
2003-01-01	51.556
2003-04-01	50.565
2003-07-01	54.103
2003-10-01	63.476
2004-01-01	94.297
2004-04-01	100.160
2004-07-01	119.187
2004-10-01	147.602
2005-01-01	154.097
2005-04-01	150.205
2005-07-01	172.618
2005-10-01	172.062
2006-01-01	182.061
2006-04-01	185.946
2006-07-01	196.572
2006-10-01	191.722
2007-01-01	215.443
2007-04-01	221.143
2007-07-01	244.749
2007-10-01	228.214
2008-01-01	252.844
2008-04-01	280.483
2008-07-01	259.113
2008-10-01	221.191
2009-01-01	207.927
2009-04-01	220.284
2009-07-01	225.840
2009-10-01	214.129
2010-01-01	216.960
2010-04-01	201.466
2010-07-01	221.445
2010-10-01	211.062
2011-01-01	219.991
2011-04-01	219.804
2011-07-01	212.852
2011-10-01	202.668
2012-01-01	216.908
2012-04-01	202.227
2012-07-01	203.999
2012-10-01	202.555
2013-01-01	195.252
2013-04-01	192.465
2013-07-01	184.673
2013-10-01	188.284
2014-01-01	195.826
2014-04-01	212.785
2014-07-01	225.898
2014-10-01	226.937
2015-01-01	213.221
2015-04-01	234.758