Quarter	Billions of US Dollars
1971-01-01	0.040
1971-04-01	0.040
1971-07-01	0.002
1971-10-01	0.002
1972-01-01	0.096
1972-04-01	0.098
1972-07-01	0.026
1972-10-01	0.040
1973-01-01	0.070
1974-01-01	0.178
1974-04-01	0.039
1974-07-01	0.233
1974-10-01	0.164
1975-01-01	0.703
1975-04-01	0.597
1975-07-01	0.183
1975-10-01	0.494
1976-01-01	0.922
1976-04-01	0.945
1976-07-01	0.509
1976-10-01	0.598
1977-01-01	0.452
1977-04-01	0.296
1977-07-01	0.227
1977-10-01	0.677
1978-01-01	0.412
1978-04-01	0.470
1978-07-01	0.362
1978-10-01	0.081
1979-01-01	0.388
1979-04-01	0.659
1979-07-01	0.545
1979-10-01	0.510
1980-01-01	0.318
1980-04-01	0.717
1980-07-01	0.327
1980-10-01	0.889
1981-01-01	1.110
1981-04-01	0.593
1981-07-01	0.418
1981-10-01	0.921
1982-01-01	2.606
1982-04-01	1.786
1982-07-01	1.746
1982-10-01	2.710
1983-01-01	1.893
1983-04-01	2.032
1983-07-01	1.609
1983-10-01	0.872
1984-01-01	2.235
1984-04-01	1.156
1984-07-01	2.508
1984-10-01	1.887
1985-01-01	3.574
1985-04-01	3.083
1985-07-01	2.132
1985-10-01	2.444
1986-01-01	2.723
1986-04-01	2.986
1986-07-01	3.552
1986-10-01	2.359
1987-01-01	3.254
1987-04-01	1.566
1987-07-01	0.964
1987-10-01	0.779
1988-01-01	3.753
1988-04-01	4.107
1988-07-01	3.881
1988-10-01	2.039
1989-01-01	2.631
1989-04-01	3.222
1989-07-01	2.356
1989-10-01	2.324
1990-01-01	3.718
1990-04-01	4.284
1990-07-01	3.010
1990-10-01	4.110
1991-01-01	4.953
1991-04-01	6.796
1991-07-01	6.401
1991-10-01	5.776
1992-01-01	9.013
1992-04-01	8.154
1992-07-01	6.221
1992-10-01	7.143
1993-01-01	11.845
1993-04-01	8.939
1993-07-01	9.905
1993-10-01	8.783
1994-01-01	9.904
1994-04-01	6.391
1994-07-01	4.938
1994-10-01	4.339
1995-01-01	4.909
1995-04-01	5.511
1995-07-01	4.295
1995-10-01	7.818
1996-01-01	6.827
1996-04-01	8.675
1996-07-01	8.747
1996-10-01	6.220
1997-01-01	10.405
1997-04-01	9.427
1997-07-01	4.672
1997-10-01	6.415
1998-01-01	14.755
1998-04-01	9.672
1998-07-01	6.629
1998-10-01	12.415
1999-01-01	24.603
1999-04-01	17.828
1999-07-01	10.811
1999-10-01	21.985
2000-01-01	17.760
2000-04-01	21.275
2000-07-01	17.058
2000-10-01	19.351
2001-01-01	40.319
2001-04-01	28.156
2001-07-01	19.844
2001-10-01	39.229
2002-01-01	25.540
2002-04-01	26.098
2002-07-01	21.402
2002-10-01	27.357
2003-01-01	49.170
2003-04-01	49.861
2003-07-01	32.397
2003-10-01	36.834
2004-01-01	41.036
2004-04-01	44.775
2004-07-01	38.603
2004-10-01	50.891
2005-01-01	54.341
2005-04-01	61.488
2005-07-01	26.242
2005-10-01	54.898
2006-01-01	49.429
2006-04-01	56.767
2006-07-01	50.526
2006-10-01	92.453
2007-01-01	66.230
2007-04-01	78.743
2007-07-01	35.368
2007-10-01	62.351
2008-01-01	53.931
2008-04-01	119.999
2008-07-01	58.221
2008-10-01	55.016
2009-01-01	95.195
2009-04-01	147.838
2009-07-01	81.599
2009-10-01	75.225
2010-01-01	106.090
2010-04-01	72.167
2010-07-01	72.271
2010-10-01	78.234
2011-01-01	112.666
2011-04-01	85.296
2011-07-01	46.602
2011-10-01	53.241
2012-01-01	89.296
2012-04-01	53.286
2012-07-01	43.561
2012-10-01	49.925
2013-01-01	63.004
2013-04-01	49.066
2013-07-01	52.716
2013-10-01	75.839
2014-01-01	97.331
2014-04-01	94.306
2014-07-01	69.078
2014-10-01	42.408
2015-01-01	68.583
2015-04-01	34.296