Quarter	Billions of US Dollars
1971-01-01	0.015
1971-04-01	0.015
1971-07-01	0.015
1971-10-01	0.063
1972-01-01	0.143
1972-04-01	0.175
1972-07-01	0.294
1972-10-01	0.361
1973-01-01	0.459
1973-04-01	0.506
1973-07-01	0.572
1973-10-01	0.540
1974-01-01	0.590
1974-04-01	0.591
1974-07-01	0.586
1974-10-01	0.656
1975-01-01	0.785
1975-04-01	0.813
1975-07-01	0.897
1975-10-01	0.965
1976-01-01	1.046
1976-04-01	1.083
1976-07-01	1.167
1976-10-01	1.362
1977-01-01	1.405
1977-04-01	1.503
1977-07-01	1.621
1977-10-01	1.904
1978-01-01	2.286
1978-04-01	2.589
1978-07-01	2.942
1978-10-01	3.185
1979-01-01	3.389
1979-04-01	3.536
1979-07-01	3.836
1979-10-01	3.975
1980-01-01	3.690
1980-04-01	4.047
1980-07-01	3.985
1980-10-01	3.854
1981-01-01	3.697
1981-04-01	3.731
1981-07-01	3.778
1981-10-01	4.120
1982-01-01	3.993
1982-04-01	4.105
1982-07-01	4.192
1982-10-01	4.564
1983-01-01	4.597
1983-04-01	4.726
1983-07-01	4.805
1983-10-01	4.738
1984-01-01	5.120
1984-04-01	5.186
1984-07-01	5.237
1984-10-01	5.363
1985-01-01	5.663
1985-04-01	5.880
1985-07-01	6.471
1985-10-01	6.564
1986-01-01	7.358
1986-04-01	8.098
1986-07-01	9.145
1986-10-01	9.817
1987-01-01	11.322
1987-04-01	11.691
1987-07-01	11.548
1987-10-01	13.630
1988-01-01	13.961
1988-04-01	14.493
1988-07-01	14.485
1988-10-01	16.215
1989-01-01	17.160
1989-04-01	17.202
1989-07-01	18.051
1989-10-01	19.327
1990-01-01	20.259
1990-04-01	21.974
1990-07-01	24.754
1990-10-01	26.922
1991-01-01	26.489
1991-04-01	27.538
1991-07-01	30.029
1991-10-01	32.934
1992-01-01	32.637
1992-04-01	38.656
1992-07-01	42.344
1992-10-01	42.652
1993-01-01	45.609
1993-04-01	47.277
1993-07-01	46.602
1993-10-01	44.438
1994-01-01	47.071
1994-04-01	50.165
1994-07-01	54.817
1994-10-01	54.739
1995-01-01	59.183
1995-04-01	58.952
1995-07-01	56.079
1995-10-01	53.865
1996-01-01	53.927
1996-04-01	51.791
1996-07-01	50.759
1996-10-01	50.734
1997-01-01	49.720
1997-04-01	48.963
1997-07-01	47.062
1997-10-01	43.739
1998-01-01	41.078
1998-04-01	41.430
1998-07-01	42.766
1998-10-01	41.369
1999-01-01	38.473
1999-04-01	38.022
1999-07-01	40.104
1999-10-01	38.362
2000-01-01	36.123
2000-04-01	36.942
2000-07-01	34.605
2000-10-01	33.363
2001-01-01	31.166
2001-04-01	35.422
2001-07-01	36.280
2001-10-01	34.839
2002-01-01	35.549
2002-04-01	38.256
2002-07-01	36.653
2002-10-01	38.533
2003-01-01	46.487
2003-04-01	52.686
2003-07-01	55.419
2003-10-01	59.485
2004-01-01	61.392
2004-04-01	62.691
2004-07-01	61.598
2004-10-01	68.333
2005-01-01	65.186
2005-04-01	62.260
2005-07-01	63.528
2005-10-01	64.008
2006-01-01	66.573
2006-04-01	73.220
2006-07-01	66.405
2006-10-01	70.243
2007-01-01	68.154
2007-04-01	70.299
2007-07-01	66.274
2007-10-01	66.759
2008-01-01	69.215
2008-04-01	69.409
2008-07-01	59.284
2008-10-01	56.932
2009-01-01	58.462
2009-04-01	62.728
2009-07-01	67.214
2009-10-01	68.188
2010-01-01	69.383
2010-04-01	64.645
2010-07-01	71.050
2010-10-01	77.418
2011-01-01	96.803
2011-04-01	104.013
2011-07-01	101.596
2011-10-01	100.664
2012-01-01	115.317
2012-04-01	119.814
2012-07-01	122.980
2012-10-01	128.328
2013-01-01	129.137
2013-04-01	134.724
2013-07-01	144.994
2013-10-01	152.522
2014-01-01	158.417
2014-04-01	163.782
2014-07-01	158.580
2014-10-01	155.057
2015-01-01	147.539
2015-04-01	158.769