Quarter	Billions of US Dollars
1966-01-01	0.015
1968-01-01	0.110
1968-04-01	0.145
1968-07-01	0.070
1968-10-01	0.028
1969-01-01	0.090
1969-10-01	0.008
1970-04-01	0.015
1970-10-01	0.020
1971-01-01	0.240
1971-04-01	0.095
1971-07-01	0.110
1971-10-01	0.250
1972-01-01	0.373
1972-04-01	0.500
1972-07-01	0.103
1972-10-01	0.248
1973-01-01	0.142
1973-04-01	0.039
1973-07-01	0.167
1973-10-01	0.125
1974-01-01	0.065
1974-04-01	0.010
1974-07-01	0.009
1974-10-01	0.053
1975-01-01	0.046
1975-04-01	0.157
1975-07-01	0.051
1975-10-01	0.104
1976-01-01	0.249
1976-04-01	0.055
1976-07-01	0.265
1976-10-01	0.311
1977-01-01	0.689
1977-04-01	0.573
1977-07-01	0.502
1977-10-01	0.689
1978-01-01	0.303
1978-04-01	0.100
1978-07-01	0.431
1978-10-01	0.442
1979-01-01	0.720
1979-04-01	0.948
1979-07-01	0.327
1979-10-01	0.493
1980-01-01	0.373
1980-04-01	1.308
1980-07-01	1.271
1980-10-01	1.492
1981-01-01	1.301
1981-04-01	1.014
1981-07-01	1.605
1981-10-01	1.940
1982-01-01	4.251
1982-04-01	4.718
1982-07-01	3.873
1982-10-01	3.383
1983-01-01	2.779
1983-04-01	2.525
1983-07-01	1.770
1983-10-01	3.183
1984-01-01	3.935
1984-04-01	2.593
1984-07-01	2.091
1984-10-01	1.954
1985-01-01	0.848
1985-04-01	0.634
1985-07-01	1.112
1985-10-01	-0.248
1986-01-01	0.608
1986-04-01	1.048
1986-07-01	0.947
1986-10-01	0.756
1987-01-01	0.981
1987-04-01	1.583
1987-07-01	0.565
1987-10-01	0.353
1988-01-01	0.317
1988-04-01	0.660
1988-07-01	2.195
1988-10-01	0.988
1989-01-01	3.043
1989-04-01	1.983
1989-07-01	1.627
1989-10-01	1.267
1990-01-01	1.498
1990-04-01	-0.787
1990-07-01	5.464
1990-10-01	0.431
1991-01-01	3.156
1991-04-01	0.383
1991-07-01	0.701
1991-10-01	-0.171
1992-01-01	-3.696
1992-04-01	-1.427
1992-07-01	4.140
1992-10-01	0.250
1993-01-01	-1.210
1993-04-01	-2.958
1993-07-01	2.504
1993-10-01	5.383
1994-01-01	4.504
1994-04-01	3.757
1994-07-01	6.319
1994-10-01	9.240
1995-01-01	7.175
1995-04-01	9.237
1995-07-01	9.571
1995-10-01	7.516
1996-01-01	10.310
1996-04-01	12.747
1996-07-01	13.175
1996-10-01	25.136
1997-01-01	20.568
1997-04-01	15.852
1997-07-01	29.024
1997-10-01	23.113
1998-01-01	15.716
1998-04-01	26.898
1998-07-01	11.621
1998-10-01	1.853
1999-01-01	17.749
1999-04-01	20.658
1999-07-01	18.406
1999-10-01	8.971
2000-01-01	18.599
2000-04-01	11.943
2000-07-01	20.295
2000-10-01	22.781
2001-01-01	29.396
2001-04-01	29.680
2001-07-01	19.263
2001-10-01	19.910
2002-01-01	9.309
2002-04-01	22.147
2002-07-01	-1.202
2002-10-01	0.713
2003-01-01	1.240
2003-04-01	8.994
2003-07-01	4.074
2003-10-01	7.446
2004-01-01	2.260
2004-04-01	7.217
2004-07-01	6.917
2004-10-01	8.600
2005-01-01	5.573
2005-04-01	7.864
2005-07-01	11.030
2005-10-01	47.262
2006-01-01	46.512
2006-04-01	56.107
2006-07-01	80.976
2006-10-01	126.747
2007-01-01	91.142
2007-04-01	119.555
2007-07-01	66.303
2007-10-01	27.728
2008-01-01	7.040
2008-04-01	5.979
2008-07-01	2.435
2008-10-01	-10.693
2009-01-01	-5.954
2009-04-01	4.186
2009-07-01	0.381
2009-10-01	0.035
2010-01-01	1.688
2010-04-01	-7.172
2010-07-01	21.138
2010-10-01	15.490
2011-01-01	0.022
2011-04-01	10.286
2011-07-01	-4.195
2011-10-01	11.005
2012-01-01	35.640
2012-04-01	18.714
2012-07-01	32.302
2012-10-01	47.479
2013-01-01	20.180
2013-04-01	47.194
2013-07-01	6.908
2013-10-01	28.815
2014-01-01	27.806
2014-04-01	54.805
2014-07-01	47.219
2014-10-01	28.692
2015-01-01	33.143
2015-04-01	45.533