Quarter	Billions of US Dollars
1971-10-01	0.031
1972-01-01	0.113
1972-04-01	0.153
1972-07-01	0.173
1972-10-01	0.208
1973-01-01	0.277
1973-04-01	0.289
1973-07-01	0.340
1973-10-01	0.395
1974-01-01	0.401
1974-04-01	0.398
1974-07-01	0.392
1974-10-01	0.449
1975-01-01	0.548
1975-04-01	0.624
1975-07-01	0.631
1975-10-01	0.694
1976-01-01	0.762
1976-04-01	0.905
1976-07-01	1.011
1976-10-01	1.099
1977-01-01	1.217
1977-04-01	1.540
1977-07-01	2.045
1977-10-01	2.647
1978-01-01	3.204
1978-04-01	3.331
1978-07-01	3.679
1978-10-01	3.794
1979-01-01	3.710
1979-04-01	3.724
1979-07-01	4.013
1979-10-01	3.997
1980-01-01	3.704
1980-04-01	4.113
1980-07-01	4.069
1980-10-01	4.015
1981-01-01	3.942
1981-04-01	4.285
1981-07-01	4.647
1981-10-01	5.451
1982-01-01	5.814
1982-04-01	5.749
1982-07-01	5.772
1982-10-01	5.826
1983-01-01	5.556
1983-04-01	5.419
1983-07-01	5.314
1983-10-01	5.116
1984-01-01	5.121
1984-04-01	4.936
1984-07-01	4.686
1984-10-01	4.610
1985-01-01	4.559
1985-04-01	4.543
1985-07-01	4.573
1985-10-01	4.352
1986-01-01	4.438
1986-04-01	4.370
1986-07-01	4.341
1986-10-01	4.130
1987-01-01	4.068
1987-04-01	3.899
1987-07-01	3.868
1987-10-01	3.760
1988-01-01	3.474
1988-04-01	3.033
1988-07-01	2.442
1988-10-01	2.103
1989-01-01	1.901
1989-04-01	1.850
1989-07-01	1.874
1989-10-01	1.926
1990-01-01	37.341
1990-04-01	38.016
1990-07-01	38.886
1990-10-01	39.346
1991-01-01	38.963
1991-04-01	39.768
1991-07-01	40.535
1991-10-01	41.763
1992-01-01	41.559
1992-04-01	42.092
1992-07-01	42.681
1992-10-01	44.214
1993-01-01	45.148
1993-04-01	47.413
1993-07-01	47.799
1993-10-01	49.165
1994-01-01	53.325
1994-04-01	55.403
1994-07-01	56.540
1994-10-01	56.850
1995-01-01	56.582
1995-04-01	57.317
1995-07-01	58.866
1995-10-01	59.707
1996-01-01	62.154
1996-04-01	61.659
1996-07-01	69.682
1996-10-01	69.528
1997-01-01	71.079
1997-04-01	74.881
1997-07-01	71.281
1997-10-01	70.905
1998-01-01	72.299
1998-04-01	71.430
1998-07-01	72.792
1998-10-01	74.381
1999-01-01	74.637
1999-04-01	78.731
1999-07-01	81.088
1999-10-01	82.119
2000-01-01	85.541
2000-04-01	84.991
2000-07-01	85.689
2000-10-01	83.060
2001-01-01	88.289
2001-04-01	83.760
2001-07-01	86.540
2001-10-01	80.289
2002-01-01	81.670
2002-04-01	78.118
2002-07-01	77.324
2002-10-01	80.089
2003-01-01	73.369
2003-04-01	72.620
2003-07-01	69.951
2003-10-01	71.520
2004-01-01	73.756
2004-04-01	74.466
2004-07-01	77.372
2004-10-01	78.918
2005-01-01	81.781
2005-04-01	80.185
2005-07-01	81.205
2005-10-01	81.994
2006-01-01	82.915
2006-04-01	81.636
2006-07-01	80.348
2006-10-01	83.834
2007-01-01	85.270
2007-04-01	85.664
2007-07-01	84.562
2007-10-01	88.195
2008-01-01	87.421
2008-04-01	88.329
2008-07-01	85.878
2008-10-01	81.494
2009-01-01	78.823
2009-04-01	79.949
2009-07-01	84.075
2009-10-01	92.301
2010-01-01	94.999
2010-04-01	98.296
2010-07-01	104.233
2010-10-01	101.626
2011-01-01	105.135
2011-04-01	110.900
2011-07-01	115.187
2011-10-01	118.446
2012-01-01	127.204
2012-04-01	129.086
2012-07-01	137.906
2012-10-01	144.163
2013-01-01	147.188
2013-04-01	149.922
2013-07-01	161.807
2013-10-01	172.446
2014-01-01	178.515
2014-04-01	188.032
2014-07-01	188.316
2014-10-01	191.658
2015-01-01	195.770
2015-04-01	207.664