Quarter	Billions of US Dollars
1971-01-01	0.025
1971-04-01	0.025
1971-07-01	0.025
1971-10-01	0.025
1972-01-01	0.025
1972-04-01	0.025
1972-07-01	0.025
1972-10-01	0.055
1973-01-01	0.111
1973-04-01	0.136
1973-07-01	0.209
1973-10-01	0.197
1974-01-01	0.232
1974-04-01	0.267
1974-07-01	0.265
1974-10-01	0.324
1975-01-01	0.331
1975-04-01	0.327
1975-07-01	0.300
1975-10-01	0.344
1976-01-01	0.349
1976-04-01	0.347
1976-07-01	0.376
1976-10-01	0.383
1977-01-01	0.406
1977-04-01	0.413
1977-07-01	0.484
1977-10-01	0.522
1978-01-01	0.546
1978-04-01	0.627
1978-07-01	0.697
1978-10-01	0.694
1979-01-01	0.672
1979-04-01	0.716
1979-07-01	0.843
1979-10-01	0.901
1980-01-01	0.929
1980-04-01	1.016
1980-07-01	1.012
1980-10-01	1.067
1981-01-01	1.109
1981-04-01	1.144
1981-07-01	1.079
1981-10-01	1.456
1982-01-01	1.681
1982-04-01	1.748
1982-07-01	1.884
1982-10-01	2.000
1983-01-01	2.214
1983-04-01	2.278
1983-07-01	2.292
1983-10-01	2.915
1984-01-01	2.993
1984-04-01	2.955
1984-07-01	3.214
1984-10-01	3.407
1985-01-01	3.838
1985-04-01	4.067
1985-07-01	4.582
1985-10-01	5.145
1986-01-01	5.523
1986-04-01	6.229
1986-07-01	7.495
1986-10-01	7.593
1987-01-01	7.729
1987-04-01	7.864
1987-07-01	7.755
1987-10-01	8.193
1988-01-01	8.209
1988-04-01	7.917
1988-07-01	7.400
1988-10-01	7.626
1989-01-01	7.211
1989-04-01	7.251
1989-07-01	9.258
1989-10-01	9.546
1990-01-01	9.778
1990-04-01	10.192
1990-07-01	10.473
1990-10-01	10.742
1991-01-01	9.996
1991-04-01	10.290
1991-07-01	10.771
1991-10-01	11.260
1992-01-01	10.875
1992-04-01	11.156
1992-07-01	11.976
1992-10-01	12.268
1993-01-01	14.666
1993-04-01	14.737
1993-07-01	14.714
1993-10-01	14.095
1994-01-01	13.900
1994-04-01	14.675
1994-07-01	14.614
1994-10-01	13.939
1995-01-01	15.155
1995-04-01	15.885
1995-07-01	15.631
1995-10-01	16.377
1996-01-01	19.102
1996-04-01	18.906
1996-07-01	19.462
1996-10-01	20.253
1997-01-01	20.244
1997-04-01	20.477
1997-07-01	20.790
1997-10-01	20.081
1998-01-01	20.818
1998-04-01	21.349
1998-07-01	22.599
1998-10-01	22.754
1999-01-01	22.290
1999-04-01	22.006
1999-07-01	23.822
1999-10-01	24.558
2000-01-01	25.700
2000-04-01	26.349
2000-07-01	26.293
2000-10-01	26.730
2001-01-01	30.532
2001-04-01	31.554
2001-07-01	32.905
2001-10-01	33.058
2002-01-01	33.075
2002-04-01	36.227
2002-07-01	37.392
2002-10-01	41.049
2003-01-01	43.631
2003-04-01	48.603
2003-07-01	56.621
2003-10-01	65.158
2004-01-01	68.466
2004-04-01	70.135
2004-07-01	77.667
2004-10-01	90.640
2005-01-01	90.867
2005-04-01	99.015
2005-07-01	106.577
2005-10-01	117.909
2006-01-01	126.053
2006-04-01	146.856
2006-07-01	164.074
2006-10-01	187.604
2007-01-01	222.209
2007-04-01	259.196
2007-07-01	304.647
2007-10-01	339.461
2008-01-01	367.369
2008-04-01	399.677
2008-07-01	368.134
2008-10-01	388.227
2009-01-01	389.737
2009-04-01	436.978
2009-07-01	466.387
2009-10-01	470.597
2010-01-01	469.706
2010-04-01	433.468
2010-07-01	434.720
2010-10-01	429.774
2011-01-01	443.840
2011-04-01	445.892
2011-07-01	406.621
2011-10-01	392.993
2012-01-01	394.802
2012-04-01	367.839
2012-07-01	363.319
2012-10-01	374.337
2013-01-01	371.972
2013-04-01	365.717
2013-07-01	375.812
2013-10-01	393.145
2014-01-01	394.731
2014-04-01	387.357
2014-07-01	357.127
2014-10-01	317.729
2015-01-01	263.679
2015-04-01	286.726