Quarter	Billions of US Dollars
1972-07-01	0.031
1972-10-01	0.091
1973-01-01	0.095
1973-04-01	0.126
1973-07-01	0.126
1973-10-01	0.158
1974-01-01	0.161
1974-04-01	0.159
1974-07-01	0.156
1974-10-01	0.185
1975-01-01	0.222
1975-04-01	0.221
1975-07-01	0.216
1975-10-01	0.216
1976-01-01	0.218
1976-04-01	0.267
1976-07-01	0.312
1976-10-01	0.505
1977-01-01	0.591
1977-04-01	0.798
1977-07-01	1.041
1977-10-01	1.418
1978-01-01	1.710
1978-04-01	1.896
1978-07-01	2.268
1978-10-01	2.491
1979-01-01	2.615
1979-04-01	2.658
1979-07-01	2.980
1979-10-01	3.134
1980-01-01	2.864
1980-04-01	3.407
1980-07-01	3.430
1980-10-01	3.326
1981-01-01	3.163
1981-04-01	2.904
1981-07-01	2.936
1981-10-01	3.009
1982-01-01	2.798
1982-04-01	2.646
1982-07-01	2.508
1982-10-01	2.741
1983-01-01	2.687
1983-04-01	2.601
1983-07-01	2.570
1983-10-01	2.471
1984-01-01	2.561
1984-04-01	2.310
1984-07-01	2.137
1984-10-01	1.988
1985-01-01	1.995
1985-04-01	2.019
1985-07-01	2.297
1985-10-01	1.973
1986-01-01	2.065
1986-04-01	2.076
1986-07-01	2.235
1986-10-01	2.057
1987-01-01	2.085
1987-04-01	2.040
1987-07-01	1.777
1987-10-01	1.779
1988-01-01	1.734
1988-04-01	1.301
1988-07-01	0.966
1988-10-01	0.934
1989-01-01	0.683
1989-04-01	0.588
1989-07-01	1.486
1989-10-01	1.290
1990-01-01	1.192
1990-04-01	1.177
1990-07-01	1.190
1990-10-01	1.195
1991-01-01	1.185
1991-04-01	1.116
1991-07-01	1.656
1991-10-01	2.570
1992-01-01	3.358
1992-04-01	5.090
1992-07-01	5.218
1992-10-01	5.292
1993-01-01	5.476
1993-04-01	7.294
1993-07-01	8.257
1993-10-01	10.021
1994-01-01	11.129
1994-04-01	53.712
1994-07-01	54.008
1994-10-01	55.227
1995-01-01	55.039
1995-04-01	56.190
1995-07-01	57.541
1995-10-01	58.359
1996-01-01	59.935
1996-04-01	62.851
1996-07-01	63.773
1996-10-01	68.004
1997-01-01	68.568
1997-04-01	73.634
1997-07-01	76.718
1997-10-01	75.562
1998-01-01	76.812
1998-04-01	80.503
1998-07-01	81.690
1998-10-01	72.538
1999-01-01	70.691
1999-04-01	71.866
1999-07-01	73.472
1999-10-01	76.373
2000-01-01	79.903
2000-04-01	75.996
2000-07-01	81.434
2000-10-01	82.955
2001-01-01	84.569
2001-04-01	79.135
2001-07-01	78.754
2001-10-01	76.579
2002-01-01	77.982
2002-04-01	80.025
2002-07-01	78.610
2002-10-01	77.317
2003-01-01	77.020
2003-04-01	79.777
2003-07-01	80.823
2003-10-01	84.294
2004-01-01	85.943
2004-04-01	82.029
2004-07-01	82.009
2004-10-01	81.730
2005-01-01	82.727
2005-04-01	81.375
2005-07-01	81.395
2005-10-01	80.960
2006-01-01	82.028
2006-04-01	70.892
2006-07-01	74.278
2006-10-01	76.747
2007-01-01	78.795
2007-04-01	80.887
2007-07-01	80.694
2007-10-01	80.389
2008-01-01	83.258
2008-04-01	81.794
2008-07-01	77.484
2008-10-01	74.835
2009-01-01	75.584
2009-04-01	79.485
2009-07-01	83.943
2009-10-01	90.127
2010-01-01	96.028
2010-04-01	99.879
2010-07-01	106.284
2010-10-01	112.882
2011-01-01	117.265
2011-04-01	128.792
2011-07-01	129.874
2011-10-01	133.747
2012-01-01	137.903
2012-04-01	139.646
2012-07-01	143.576
2012-10-01	146.162
2013-01-01	145.456
2013-04-01	147.596
2013-07-01	148.654
2013-10-01	151.317
2014-01-01	153.774
2014-04-01	157.069
2014-07-01	166.219
2014-10-01	161.365
2015-01-01	151.802
2015-04-01	152.829