Quarter	Billions of US Dollars
1968-07-01	0.040
1969-01-01	0.095
1969-04-01	0.015
1969-07-01	0.020
1971-10-01	0.015
1972-01-01	0.020
1972-04-01	0.150
1972-07-01	0.188
1972-10-01	0.107
1973-01-01	0.166
1973-04-01	0.080
1973-07-01	0.057
1973-10-01	0.092
1974-01-01	0.019
1974-04-01	0.120
1974-07-01	0.244
1974-10-01	0.252
1975-01-01	0.259
1975-04-01	0.228
1975-07-01	0.140
1975-10-01	0.072
1976-01-01	0.071
1976-04-01	0.391
1976-07-01	0.190
1976-10-01	0.113
1977-01-01	0.262
1977-04-01	0.210
1977-07-01	0.320
1977-10-01	0.118
1978-01-01	0.170
1978-04-01	0.204
1978-07-01	0.334
1978-10-01	0.134
1979-01-01	0.776
1979-04-01	0.354
1979-07-01	0.176
1979-10-01	0.303
1980-01-01	0.344
1980-04-01	1.000
1980-07-01	0.869
1980-10-01	0.836
1981-01-01	0.508
1981-04-01	0.780
1981-07-01	0.590
1981-10-01	0.824
1982-01-01	0.251
1982-04-01	0.563
1982-07-01	0.510
1982-10-01	1.558
1983-01-01	1.587
1983-04-01	1.437
1983-07-01	0.612
1983-10-01	2.197
1984-01-01	3.201
1984-04-01	1.394
1984-07-01	1.620
1984-10-01	1.542
1985-01-01	1.389
1985-04-01	1.207
1985-07-01	0.856
1985-10-01	1.381
1986-01-01	2.061
1986-04-01	2.398
1986-07-01	2.858
1986-10-01	2.399
1987-01-01	4.265
1987-04-01	2.760
1987-07-01	1.524
1987-10-01	1.129
1988-01-01	4.275
1988-04-01	3.169
1988-07-01	3.260
1988-10-01	4.411
1989-01-01	2.067
1989-04-01	3.875
1989-07-01	3.127
1989-10-01	3.338
1990-01-01	4.708
1990-04-01	2.131
1990-07-01	2.828
1990-10-01	3.392
1991-01-01	5.895
1991-04-01	3.498
1991-07-01	2.802
1991-10-01	5.904
1992-01-01	6.194
1992-04-01	3.425
1992-07-01	4.386
1992-10-01	4.798
1993-01-01	8.451
1993-04-01	6.458
1993-07-01	9.392
1993-10-01	9.905
1994-01-01	10.878
1994-04-01	6.738
1994-07-01	9.889
1994-10-01	11.045
1995-01-01	10.621
1995-04-01	12.046
1995-07-01	10.281
1995-10-01	9.572
1996-01-01	18.220
1996-04-01	15.626
1996-07-01	10.169
1996-10-01	11.706
1997-01-01	17.996
1997-04-01	14.126
1997-07-01	16.601
1997-10-01	13.337
1998-01-01	21.019
1998-04-01	20.340
1998-07-01	17.952
1998-10-01	16.884
1999-01-01	32.777
1999-04-01	48.947
1999-07-01	30.413
1999-10-01	26.653
2000-01-01	28.206
2000-04-01	45.500
2000-07-01	38.513
2000-10-01	32.986
2001-01-01	37.463
2001-04-01	43.050
2001-07-01	29.392
2001-10-01	39.509
2002-01-01	33.869
2002-04-01	44.212
2002-07-01	36.043
2002-10-01	30.285
2003-01-01	44.581
2003-04-01	67.195
2003-07-01	48.935
2003-10-01	53.794
2004-01-01	48.649
2004-04-01	41.960
2004-07-01	34.570
2004-10-01	52.392
2005-01-01	60.467
2005-04-01	57.827
2005-07-01	45.405
2005-10-01	63.003
2006-01-01	77.513
2006-04-01	86.557
2006-07-01	72.695
2006-10-01	104.788
2007-01-01	114.241
2007-04-01	91.852
2007-07-01	61.107
2007-10-01	72.481
2008-01-01	67.608
2008-04-01	126.894
2008-07-01	51.126
2008-10-01	84.492
2009-01-01	142.773
2009-04-01	131.406
2009-07-01	67.155
2009-10-01	66.815
2010-01-01	116.719
2010-04-01	47.829
2010-07-01	89.127
2010-10-01	57.561
2011-01-01	89.435
2011-04-01	92.494
2011-07-01	56.790
2011-10-01	78.306
2012-01-01	132.641
2012-04-01	57.508
2012-07-01	114.730
2012-10-01	75.572
2013-01-01	83.253
2013-04-01	91.556
2013-07-01	87.455
2013-10-01	99.967
2014-01-01	134.509
2014-04-01	97.467
2014-07-01	59.103
2014-10-01	58.130
2015-01-01	82.616
2015-04-01	84.871