Quarter	Billions of US Dollars
1972-07-01	0.050
1972-10-01	0.050
1973-01-01	0.050
1973-04-01	0.080
1973-07-01	0.080
1973-10-01	0.080
1974-01-01	0.080
1974-04-01	0.131
1974-07-01	0.131
1974-10-01	0.132
1975-01-01	0.193
1975-04-01	0.275
1975-07-01	0.268
1975-10-01	0.288
1976-01-01	0.315
1976-04-01	0.354
1976-07-01	0.375
1976-10-01	0.378
1977-01-01	0.407
1977-04-01	0.428
1977-07-01	0.573
1977-10-01	0.695
1978-01-01	0.703
1978-04-01	0.749
1978-07-01	0.765
1978-10-01	0.771
1979-01-01	0.762
1979-04-01	0.858
1979-07-01	0.865
1979-10-01	0.861
1980-01-01	0.814
1980-04-01	0.895
1980-07-01	0.905
1980-10-01	0.896
1981-01-01	0.850
1981-04-01	0.735
1981-07-01	0.734
1981-10-01	0.744
1982-01-01	0.726
1982-04-01	0.721
1982-07-01	0.686
1982-10-01	0.682
1983-01-01	0.617
1983-04-01	0.554
1983-07-01	0.519
1983-10-01	0.501
1984-01-01	0.506
1984-04-01	0.445
1984-07-01	0.487
1984-10-01	0.482
1985-01-01	0.654
1985-04-01	0.635
1985-07-01	0.830
1985-10-01	0.806
1986-01-01	1.009
1986-04-01	1.433
1986-07-01	1.553
1986-10-01	1.655
1987-01-01	2.085
1987-04-01	2.068
1987-07-01	2.066
1987-10-01	2.729
1988-01-01	3.451
1988-04-01	3.690
1988-07-01	4.150
1988-10-01	5.036
1989-01-01	5.713
1989-04-01	5.752
1989-07-01	7.278
1989-10-01	8.098
1990-01-01	8.688
1990-04-01	9.083
1990-07-01	10.104
1990-10-01	10.865
1991-01-01	10.104
1991-04-01	10.171
1991-07-01	10.960
1991-10-01	13.192
1992-01-01	13.250
1992-04-01	14.273
1992-07-01	16.378
1992-10-01	15.991
1993-01-01	18.723
1993-04-01	20.268
1993-07-01	22.769
1993-10-01	23.771
1994-01-01	26.278
1994-04-01	27.552
1994-07-01	33.564
1994-10-01	39.858
1995-01-01	41.820
1995-04-01	42.933
1995-07-01	42.212
1995-10-01	42.290
1996-01-01	41.907
1996-04-01	43.029
1996-07-01	40.833
1996-10-01	40.429
1997-01-01	41.462
1997-04-01	46.998
1997-07-01	50.758
1997-10-01	52.017
1998-01-01	53.983
1998-04-01	59.328
1998-07-01	67.127
1998-10-01	67.551
1999-01-01	66.907
1999-04-01	66.856
1999-07-01	68.449
1999-10-01	71.573
2000-01-01	72.540
2000-04-01	75.466
2000-07-01	94.288
2000-10-01	94.495
2001-01-01	94.419
2001-04-01	93.938
2001-07-01	95.988
2001-10-01	95.695
2002-01-01	96.511
2002-04-01	101.394
2002-07-01	101.701
2002-10-01	104.953
2003-01-01	111.467
2003-04-01	114.174
2003-07-01	119.765
2003-10-01	126.488
2004-01-01	128.743
2004-04-01	136.371
2004-07-01	141.610
2004-10-01	152.082
2005-01-01	160.244
2005-04-01	172.412
2005-07-01	173.048
2005-10-01	181.817
2006-01-01	195.642
2006-04-01	202.181
2006-07-01	210.027
2006-10-01	234.950
2007-01-01	252.389
2007-04-01	271.371
2007-07-01	278.814
2007-10-01	294.812
2008-01-01	302.902
2008-04-01	324.820
2008-07-01	316.734
2008-10-01	308.702
2009-01-01	299.687
2009-04-01	315.461
2009-07-01	325.919
2009-10-01	331.404
2010-01-01	331.997
2010-04-01	328.230
2010-07-01	361.309
2010-10-01	377.361
2011-01-01	401.320
2011-04-01	419.370
2011-07-01	407.239
2011-10-01	402.100
2012-01-01	423.030
2012-04-01	438.601
2012-07-01	484.090
2012-10-01	526.151
2013-01-01	535.233
2013-04-01	558.852
2013-07-01	574.939
2013-10-01	604.859
2014-01-01	595.893
2014-04-01	592.886
2014-07-01	576.367
2014-10-01	571.921
2015-01-01	551.733
2015-04-01	558.247