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	0.585
1975-04-01	0.661
1975-07-01	0.668
1975-10-01	0.732
1976-01-01	0.800
1976-04-01	0.943
1976-07-01	1.048
1976-10-01	1.137
1977-01-01	1.254
1977-04-01	1.578
1977-07-01	2.083
1977-10-01	2.684
1978-01-01	3.242
1978-04-01	3.369
1978-07-01	3.717
1978-10-01	3.832
1979-01-01	3.812
1979-04-01	3.827
1979-07-01	4.115
1979-10-01	4.100
1980-01-01	3.806
1980-04-01	4.256
1980-07-01	4.237
1980-10-01	4.182
1981-01-01	4.110
1981-04-01	4.453
1981-07-01	4.899
1981-10-01	5.803
1982-01-01	6.266
1982-04-01	6.302
1982-07-01	6.324
1982-10-01	6.379
1983-01-01	6.109
1983-04-01	5.971
1983-07-01	5.866
1983-10-01	5.669
1984-01-01	5.673
1984-04-01	5.488
1984-07-01	5.239
1984-10-01	5.162
1985-01-01	5.112
1985-04-01	5.095
1985-07-01	5.126
1985-10-01	4.889
1986-01-01	4.974
1986-04-01	4.907
1986-07-01	4.877
1986-10-01	4.525
1987-01-01	4.364
1987-04-01	4.158
1987-07-01	4.128
1987-10-01	4.019
1988-01-01	3.734
1988-04-01	3.293
1988-07-01	2.701
1988-10-01	2.362
1989-01-01	2.160
1989-04-01	2.078
1989-07-01	2.017
1989-10-01	2.068
1990-01-01	37.419
1990-04-01	38.024
1990-07-01	39.166
1990-10-01	39.578
1991-01-01	39.201
1991-04-01	39.978
1991-07-01	40.887
1991-10-01	42.452
1992-01-01	42.081
1992-04-01	42.639
1992-07-01	43.564
1992-10-01	45.426
1993-01-01	46.341
1993-04-01	48.750
1993-07-01	48.377
1993-10-01	49.582
1994-01-01	53.638
1994-04-01	54.990
1994-07-01	56.037
1994-10-01	56.075
1995-01-01	55.643
1995-04-01	56.113
1995-07-01	57.972
1995-10-01	59.002
1996-01-01	61.494
1996-04-01	60.560
1996-07-01	68.658
1996-10-01	69.128
1997-01-01	70.896
1997-04-01	76.284
1997-07-01	72.364
1997-10-01	71.899
1998-01-01	73.238
1998-04-01	73.011
1998-07-01	74.314
1998-10-01	74.439
1999-01-01	73.498
1999-04-01	77.401
1999-07-01	78.505
1999-10-01	79.226
2000-01-01	81.557
2000-04-01	81.139
2000-07-01	81.231
2000-10-01	78.950
2001-01-01	83.170
2001-04-01	78.591
2001-07-01	80.864
2001-10-01	74.575
2002-01-01	74.315
2002-04-01	70.831
2002-07-01	70.402
2002-10-01	71.987
2003-01-01	64.096
2003-04-01	61.493
2003-07-01	57.929
2003-10-01	59.781
2004-01-01	60.729
2004-04-01	59.745
2004-07-01	60.066
2004-10-01	61.025
2005-01-01	63.287
2005-04-01	63.277
2005-07-01	63.348
2005-10-01	63.863
2006-01-01	64.738
2006-04-01	63.981
2006-07-01	62.698
2006-10-01	63.947
2007-01-01	63.589
2007-04-01	64.297
2007-07-01	65.285
2007-10-01	67.360
2008-01-01	67.078
2008-04-01	66.526
2008-07-01	64.830
2008-10-01	62.248
2009-01-01	60.463
2009-04-01	64.067
2009-07-01	68.315
2009-10-01	76.570
2010-01-01	80.718
2010-04-01	87.394
2010-07-01	92.323
2010-10-01	92.773
2011-01-01	98.129
2011-04-01	104.021
2011-07-01	108.429
2011-10-01	112.280
2012-01-01	120.237
2012-04-01	121.753
2012-07-01	132.244
2012-10-01	138.433
2013-01-01	141.782
2013-04-01	146.898
2013-07-01	158.247
2013-10-01	173.017
2014-01-01	180.264
2014-04-01	191.114
2014-07-01	191.568
2014-10-01	195.195
2015-01-01	199.799
2015-04-01	209.294