Quarter	Billions of US Dollars
1966-01-01	0.080
1966-04-01	0.045
1966-07-01	0.030
1966-10-01	0.020
1967-01-01	0.039
1967-04-01	0.130
1967-07-01	0.020
1967-10-01	0.022
1968-01-01	0.299
1968-04-01	0.495
1968-07-01	0.210
1968-10-01	0.091
1969-01-01	0.227
1969-04-01	0.030
1969-07-01	0.030
1969-10-01	0.158
1970-01-01	0.073
1970-04-01	0.015
1970-07-01	0.275
1970-10-01	0.035
1971-01-01	0.988
1971-04-01	0.508
1971-07-01	0.283
1971-10-01	0.847
1972-01-01	2.955
1972-04-01	2.491
1972-07-01	2.378
1972-10-01	2.950
1973-01-01	2.553
1973-04-01	2.302
1973-07-01	1.552
1973-10-01	2.440
1974-01-01	1.611
1974-04-01	2.163
1974-07-01	1.806
1974-10-01	3.336
1975-01-01	4.578
1975-04-01	5.589
1975-07-01	4.176
1975-10-01	7.271
1976-01-01	9.506
1976-04-01	7.506
1976-07-01	7.716
1976-10-01	9.083
1977-01-01	7.876
1977-04-01	8.658
1977-07-01	8.603
1977-10-01	8.562
1978-01-01	9.664
1978-04-01	9.236
1978-07-01	8.917
1978-10-01	7.038
1979-01-01	9.069
1979-04-01	8.865
1979-07-01	8.023
1979-10-01	6.378
1980-01-01	5.015
1980-04-01	9.856
1980-07-01	6.077
1980-10-01	7.273
1981-01-01	6.555
1981-04-01	8.396
1981-07-01	8.913
1981-10-01	14.377
1982-01-01	16.562
1982-04-01	13.351
1982-07-01	15.192
1982-10-01	13.755
1983-01-01	15.917
1983-04-01	14.012
1983-07-01	8.437
1983-10-01	17.582
1984-01-01	20.517
1984-04-01	14.077
1984-07-01	19.977
1984-10-01	29.035
1985-01-01	24.151
1985-04-01	24.050
1985-07-01	25.385
1985-10-01	17.621
1986-01-01	31.034
1986-04-01	39.651
1986-07-01	37.858
1986-10-01	28.070
1987-01-01	31.939
1987-04-01	29.008
1987-07-01	22.938
1987-10-01	11.027
1988-01-01	22.832
1988-04-01	32.771
1988-07-01	38.542
1988-10-01	25.615
1989-01-01	47.109
1989-04-01	44.183
1989-07-01	32.967
1989-10-01	38.080
1990-01-01	69.652
1990-04-01	21.745
1990-07-01	40.990
1990-10-01	53.826
1991-01-01	51.608
1991-04-01	48.011
1991-07-01	40.265
1991-10-01	44.767
1992-01-01	37.558
1992-04-01	36.442
1992-07-01	19.694
1992-10-01	55.623
1993-01-01	42.691
1993-04-01	57.430
1993-07-01	50.915
1993-10-01	67.590
1994-01-01	71.162
1994-04-01	74.879
1994-07-01	72.146
1994-10-01	61.621
1995-01-01	52.859
1995-04-01	51.671
1995-07-01	70.348
1995-10-01	58.459
1996-01-01	95.662
1996-04-01	99.803
1996-07-01	107.673
1996-10-01	135.577
1997-01-01	132.838
1997-04-01	130.506
1997-07-01	133.483
1997-10-01	45.827
1998-01-01	144.391
1998-04-01	179.755
1998-07-01	95.865
1998-10-01	40.154
1999-01-01	178.278
1999-04-01	245.531
1999-07-01	201.028
1999-10-01	124.076
2000-01-01	182.983
2000-04-01	196.957
2000-07-01	235.147
2000-10-01	218.898
2001-01-01	357.601
2001-04-01	317.578
2001-07-01	196.909
2001-10-01	279.600
2002-01-01	241.755
2002-04-01	259.388
2002-07-01	102.153
2002-10-01	142.606
2003-01-01	224.132
2003-04-01	278.048
2003-07-01	268.413
2003-10-01	316.746
2004-01-01	339.995
2004-04-01	260.450
2004-07-01	267.174
2004-10-01	325.908
2005-01-01	342.357
2005-04-01	358.379
2005-07-01	180.195
2005-10-01	483.128
2006-01-01	449.226
2006-04-01	451.870
2006-07-01	456.846
2006-10-01	732.715
2007-01-01	641.031
2007-04-01	853.467
2007-07-01	280.701
2007-10-01	310.597
2008-01-01	179.356
2008-04-01	741.198
2008-07-01	213.589
2008-10-01	451.639
2009-01-01	367.006
2009-04-01	580.596
2009-07-01	298.663
2009-10-01	279.539
2010-01-01	303.496
2010-04-01	16.372
2010-07-01	240.316
2010-10-01	95.514
2011-01-01	213.529
2011-04-01	147.044
2011-07-01	6.215
2011-10-01	66.962
2012-01-01	356.605
2012-04-01	-39.242
2012-07-01	148.585
2012-10-01	245.962
2013-01-01	13.125
2013-04-01	105.573
2013-07-01	111.675
2013-10-01	265.695
2014-01-01	57.606
2014-04-01	249.657
2014-07-01	198.292
2014-10-01	76.992
2015-01-01	175.534
2015-04-01	243.979