Quarter	Billions of US Dollars
1971-01-01	0.058
1971-04-01	0.087
1971-07-01	0.114
1971-10-01	0.166
1972-01-01	0.341
1972-04-01	0.420
1972-07-01	0.534
1972-10-01	0.755
1973-01-01	0.857
1973-04-01	1.231
1973-07-01	1.288
1973-10-01	1.639
1974-01-01	1.786
1974-04-01	2.205
1974-07-01	2.253
1974-10-01	2.385
1975-01-01	2.506
1975-04-01	2.833
1975-07-01	2.878
1975-10-01	2.968
1976-01-01	3.092
1976-04-01	3.287
1976-07-01	3.407
1976-10-01	3.669
1977-01-01	3.872
1977-04-01	4.090
1977-07-01	4.266
1977-10-01	4.625
1978-01-01	5.086
1978-04-01	5.537
1978-07-01	6.051
1978-10-01	6.533
1979-01-01	6.633
1979-04-01	6.828
1979-07-01	7.172
1979-10-01	7.137
1980-01-01	6.821
1980-04-01	7.052
1980-07-01	7.101
1980-10-01	6.838
1981-01-01	6.691
1981-04-01	6.390
1981-07-01	6.438
1981-10-01	6.497
1982-01-01	6.326
1982-04-01	6.295
1982-07-01	6.180
1982-10-01	6.416
1983-01-01	6.484
1983-04-01	6.444
1983-07-01	6.372
1983-10-01	6.286
1984-01-01	6.399
1984-04-01	6.473
1984-07-01	6.441
1984-10-01	6.681
1985-01-01	6.777
1985-04-01	7.511
1985-07-01	7.883
1985-10-01	6.999
1986-01-01	6.964
1986-04-01	7.047
1986-07-01	7.351
1986-10-01	7.235
1987-01-01	7.261
1987-04-01	7.001
1987-07-01	6.684
1987-10-01	6.731
1988-01-01	6.358
1988-04-01	5.876
1988-07-01	5.750
1988-10-01	5.970
1989-01-01	5.519
1989-04-01	5.112
1989-07-01	5.196
1989-10-01	5.319
1990-01-01	5.134
1990-04-01	4.441
1990-07-01	4.297
1990-10-01	4.037
1991-01-01	3.526
1991-04-01	4.279
1991-07-01	4.258
1991-10-01	4.567
1992-01-01	6.887
1992-04-01	7.634
1992-07-01	7.927
1992-10-01	7.310
1993-01-01	7.642
1993-04-01	5.685
1993-07-01	7.063
1993-10-01	7.649
1994-01-01	8.418
1994-04-01	8.118
1994-07-01	8.072
1994-10-01	8.714
1995-01-01	9.373
1995-04-01	9.589
1995-07-01	9.656
1995-10-01	9.994
1996-01-01	10.066
1996-04-01	10.137
1996-07-01	10.462
1996-10-01	12.712
1997-01-01	12.447
1997-04-01	13.264
1997-07-01	14.243
1997-10-01	14.516
1998-01-01	16.193
1998-04-01	16.360
1998-07-01	16.873
1998-10-01	17.453
1999-01-01	17.926
1999-04-01	20.473
1999-07-01	21.067
1999-10-01	21.207
2000-01-01	22.263
2000-04-01	24.078
2000-07-01	24.617
2000-10-01	24.495
2001-01-01	24.575
2001-04-01	25.416
2001-07-01	27.640
2001-10-01	27.023
2002-01-01	27.629
2002-04-01	30.137
2002-07-01	30.666
2002-10-01	30.823
2003-01-01	31.447
2003-04-01	33.993
2003-07-01	34.923
2003-10-01	35.881
2004-01-01	38.109
2004-04-01	40.486
2004-07-01	40.280
2004-10-01	43.757
2005-01-01	44.246
2005-04-01	46.666
2005-07-01	50.802
2005-10-01	53.488
2006-01-01	63.357
2006-04-01	69.611
2006-07-01	71.456
2006-10-01	85.038
2007-01-01	88.906
2007-04-01	98.035
2007-07-01	104.794
2007-10-01	112.694
2008-01-01	113.331
2008-04-01	121.077
2008-07-01	119.276
2008-10-01	117.491
2009-01-01	115.644
2009-04-01	126.059
2009-07-01	136.403
2009-10-01	138.474
2010-01-01	140.322
2010-04-01	140.760
2010-07-01	148.268
2010-10-01	153.467
2011-01-01	160.406
2011-04-01	159.737
2011-07-01	156.040
2011-10-01	167.908
2012-01-01	171.924
2012-04-01	168.543
2012-07-01	176.072
2012-10-01	189.099
2013-01-01	192.266
2013-04-01	194.191
2013-07-01	200.581
2013-10-01	205.877
2014-01-01	210.459
2014-04-01	221.361
2014-07-01	224.111
2014-10-01	232.903
2015-01-01	235.420
2015-04-01	249.045