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	0.451
1973-04-01	0.498
1973-07-01	0.564
1973-10-01	0.532
1974-01-01	0.582
1974-04-01	0.583
1974-07-01	0.578
1974-10-01	0.648
1975-01-01	0.777
1975-04-01	0.805
1975-07-01	0.889
1975-10-01	0.957
1976-01-01	1.038
1976-04-01	1.075
1976-07-01	1.159
1976-10-01	1.354
1977-01-01	1.397
1977-04-01	1.465
1977-07-01	1.583
1977-10-01	1.866
1978-01-01	2.248
1978-04-01	2.551
1978-07-01	2.904
1978-10-01	3.147
1979-01-01	3.351
1979-04-01	3.498
1979-07-01	3.798
1979-10-01	3.937
1980-01-01	3.652
1980-04-01	4.009
1980-07-01	3.947
1980-10-01	3.816
1981-01-01	3.659
1981-04-01	3.693
1981-07-01	3.740
1981-10-01	4.082
1982-01-01	3.955
1982-04-01	3.992
1982-07-01	4.079
1982-10-01	4.445
1983-01-01	4.479
1983-04-01	4.638
1983-07-01	4.718
1983-10-01	4.646
1984-01-01	4.932
1984-04-01	4.999
1984-07-01	5.010
1984-10-01	5.037
1985-01-01	5.338
1985-04-01	5.517
1985-07-01	5.969
1985-10-01	6.079
1986-01-01	6.758
1986-04-01	7.514
1986-07-01	8.290
1986-10-01	8.469
1987-01-01	9.580
1987-04-01	9.790
1987-07-01	9.665
1987-10-01	11.476
1988-01-01	11.803
1988-04-01	12.312
1988-07-01	12.267
1988-10-01	13.314
1989-01-01	13.744
1989-04-01	13.864
1989-07-01	14.572
1989-10-01	15.224
1990-01-01	15.769
1990-04-01	17.077
1990-07-01	19.321
1990-10-01	21.568
1991-01-01	21.361
1991-04-01	21.803
1991-07-01	24.165
1991-10-01	27.424
1992-01-01	27.708
1992-04-01	33.502
1992-07-01	37.051
1992-10-01	38.101
1993-01-01	41.707
1993-04-01	43.568
1993-07-01	41.271
1993-10-01	39.204
1994-01-01	41.631
1994-04-01	45.098
1994-07-01	49.646
1994-10-01	49.553
1995-01-01	53.981
1995-04-01	53.953
1995-07-01	51.056
1995-10-01	49.427
1996-01-01	50.312
1996-04-01	48.824
1996-07-01	48.203
1996-10-01	48.323
1997-01-01	47.329
1997-04-01	47.046
1997-07-01	44.979
1997-10-01	41.662
1998-01-01	39.076
1998-04-01	39.563
1998-07-01	41.325
1998-10-01	40.277
1999-01-01	37.322
1999-04-01	36.539
1999-07-01	39.115
1999-10-01	38.153
2000-01-01	35.158
2000-04-01	36.108
2000-07-01	34.032
2000-10-01	33.500
2001-01-01	31.441
2001-04-01	35.775
2001-07-01	36.521
2001-10-01	35.459
2002-01-01	36.590
2002-04-01	39.565
2002-07-01	37.916
2002-10-01	40.305
2003-01-01	48.470
2003-04-01	54.457
2003-07-01	57.237
2003-10-01	59.760
2004-01-01	60.996
2004-04-01	62.424
2004-07-01	61.513
2004-10-01	67.925
2005-01-01	66.426
2005-04-01	62.646
2005-07-01	62.362
2005-10-01	62.175
2006-01-01	64.998
2006-04-01	71.238
2006-07-01	63.379
2006-10-01	66.197
2007-01-01	63.773
2007-04-01	65.875
2007-07-01	61.907
2007-10-01	61.730
2008-01-01	63.962
2008-04-01	64.007
2008-07-01	54.297
2008-10-01	52.101
2009-01-01	54.598
2009-04-01	59.358
2009-07-01	63.751
2009-10-01	64.729
2010-01-01	66.095
2010-04-01	62.551
2010-07-01	70.169
2010-10-01	72.880
2011-01-01	90.091
2011-04-01	92.502
2011-07-01	88.502
2011-10-01	86.887
2012-01-01	96.581
2012-04-01	99.597
2012-07-01	101.776
2012-10-01	106.718
2013-01-01	107.606
2013-04-01	112.184
2013-07-01	119.425
2013-10-01	124.560
2014-01-01	127.568
2014-04-01	134.717
2014-07-01	131.899
2014-10-01	127.814
2015-01-01	121.358
2015-04-01	131.305