Quarter	Billions of US Dollars
1971-10-01	0.031
1972-01-01	0.113
1972-04-01	0.153
1972-07-01	0.204
1972-10-01	0.349
1973-01-01	0.456
1973-04-01	0.499
1973-07-01	0.575
1973-10-01	0.669
1974-01-01	0.683
1974-04-01	0.679
1974-07-01	0.671
1974-10-01	0.757
1975-01-01	0.893
1975-04-01	1.038
1975-07-01	1.064
1975-10-01	1.128
1976-01-01	1.198
1976-04-01	1.390
1976-07-01	1.540
1976-10-01	1.822
1977-01-01	2.141
1977-04-01	2.779
1977-07-01	3.716
1977-10-01	4.984
1978-01-01	6.316
1978-04-01	7.040
1978-07-01	7.871
1978-10-01	8.545
1979-01-01	8.903
1979-04-01	9.163
1979-07-01	9.871
1979-10-01	10.048
1980-01-01	9.400
1980-04-01	10.639
1980-07-01	10.849
1980-10-01	10.845
1981-01-01	10.610
1981-04-01	10.790
1981-07-01	11.312
1981-10-01	12.493
1982-01-01	12.576
1982-04-01	12.184
1982-07-01	11.954
1982-10-01	12.368
1983-01-01	11.774
1983-04-01	11.492
1983-07-01	11.370
1983-10-01	11.066
1984-01-01	11.117
1984-04-01	10.607
1984-07-01	9.969
1984-10-01	9.691
1985-01-01	9.692
1985-04-01	9.717
1985-07-01	10.302
1985-10-01	9.635
1986-01-01	9.959
1986-04-01	9.954
1986-07-01	10.172
1986-10-01	9.556
1987-01-01	9.499
1987-04-01	9.201
1987-07-01	8.879
1987-10-01	9.208
1988-01-01	8.910
1988-04-01	7.699
1988-07-01	6.761
1988-10-01	6.808
1989-01-01	6.441
1989-04-01	6.121
1989-07-01	6.966
1989-10-01	6.556
1990-01-01	41.773
1990-04-01	42.707
1990-07-01	43.518
1990-10-01	60.140
1991-01-01	60.808
1991-04-01	61.703
1991-07-01	63.312
1991-10-01	66.522
1992-01-01	67.365
1992-04-01	70.071
1992-07-01	71.594
1992-10-01	73.323
1993-01-01	74.782
1993-04-01	96.464
1993-07-01	99.810
1993-10-01	115.465
1994-01-01	121.817
1994-04-01	166.615
1994-07-01	169.417
1994-10-01	173.074
1995-01-01	178.822
1995-04-01	182.334
1995-07-01	185.988
1995-10-01	189.859
1996-01-01	195.790
1996-04-01	203.924
1996-07-01	214.829
1996-10-01	221.778
1997-01-01	233.777
1997-04-01	247.669
1997-07-01	257.579
1997-10-01	256.775
1998-01-01	262.889
1998-04-01	276.401
1998-07-01	282.628
1998-10-01	263.289
1999-01-01	262.414
1999-04-01	274.215
1999-07-01	282.035
1999-10-01	288.235
2000-01-01	300.482
2000-04-01	299.007
2000-07-01	310.545
2000-10-01	308.276
2001-01-01	316.088
2001-04-01	309.888
2001-07-01	317.364
2001-10-01	310.731
2002-01-01	313.877
2002-04-01	318.793
2002-07-01	318.152
2002-10-01	323.221
2003-01-01	319.698
2003-04-01	323.747
2003-07-01	325.516
2003-10-01	336.048
2004-01-01	340.582
2004-04-01	336.926
2004-07-01	339.794
2004-10-01	350.459
2005-01-01	353.908
2005-04-01	319.244
2005-07-01	322.292
2005-10-01	328.784
2006-01-01	335.265
2006-04-01	321.062
2006-07-01	325.761
2006-10-01	341.058
2007-01-01	348.293
2007-04-01	365.589
2007-07-01	364.071
2007-10-01	373.156
2008-01-01	373.691
2008-04-01	378.147
2008-07-01	365.462
2008-10-01	350.334
2009-01-01	347.237
2009-04-01	349.547
2009-07-01	370.448
2009-10-01	402.711
2010-01-01	411.356
2010-04-01	422.100
2010-07-01	451.953
2010-10-01	463.245
2011-01-01	488.339
2011-04-01	508.556
2011-07-01	512.448
2011-10-01	535.074
2012-01-01	571.309
2012-04-01	578.151
2012-07-01	603.622
2012-10-01	627.969
2013-01-01	643.752
2013-04-01	670.555
2013-07-01	695.753
2013-10-01	721.560
2014-01-01	746.097
2014-04-01	781.737
2014-07-01	800.279
2014-10-01	798.113
2015-01-01	793.937
2015-04-01	819.085