Quarter	Billions of US Dollars
1971-10-01	0.015
1972-01-01	0.035
1972-04-01	0.087
1972-07-01	0.086
1972-10-01	0.106
1973-01-01	0.110
1973-04-01	0.116
1973-07-01	0.193
1973-10-01	0.217
1974-01-01	0.271
1974-04-01	0.271
1974-07-01	0.279
1974-10-01	0.287
1975-01-01	0.313
1975-04-01	0.325
1975-07-01	0.316
1975-10-01	0.338
1976-01-01	0.341
1976-04-01	0.366
1976-07-01	0.430
1976-10-01	0.518
1977-01-01	0.580
1977-04-01	0.693
1977-07-01	0.778
1977-10-01	0.866
1978-01-01	1.003
1978-04-01	1.013
1978-07-01	1.069
1978-10-01	1.109
1979-01-01	1.187
1979-04-01	1.179
1979-07-01	1.187
1979-10-01	1.175
1980-01-01	1.139
1980-04-01	1.173
1980-07-01	1.196
1980-10-01	1.188
1981-01-01	1.237
1981-04-01	1.197
1981-07-01	1.153
1981-10-01	1.212
1982-01-01	1.160
1982-04-01	1.145
1982-07-01	1.180
1982-10-01	1.228
1983-01-01	1.143
1983-04-01	1.110
1983-07-01	1.139
1983-10-01	1.253
1984-01-01	1.343
1984-04-01	1.325
1984-07-01	1.285
1984-10-01	1.353
1985-01-01	1.418
1985-04-01	1.530
1985-07-01	1.534
1985-10-01	1.579
1986-01-01	1.515
1986-04-01	1.518
1986-07-01	1.685
1986-10-01	1.851
1987-01-01	1.955
1987-04-01	2.318
1987-07-01	2.291
1987-10-01	2.505
1988-01-01	2.537
1988-04-01	2.511
1988-07-01	2.408
1988-10-01	2.473
1989-01-01	2.395
1989-04-01	2.478
1989-07-01	2.448
1989-10-01	2.229
1990-01-01	2.478
1990-04-01	2.847
1990-07-01	3.283
1990-10-01	3.003
1991-01-01	3.011
1991-04-01	3.493
1991-07-01	3.787
1991-10-01	3.857
1992-01-01	3.843
1992-04-01	4.165
1992-07-01	4.290
1992-10-01	4.000
1993-01-01	3.812
1993-04-01	4.959
1993-07-01	4.539
1993-10-01	7.330
1994-01-01	9.414
1994-04-01	10.344
1994-07-01	11.289
1994-10-01	13.521
1995-01-01	13.688
1995-04-01	13.687
1995-07-01	14.166
1995-10-01	15.350
1996-01-01	17.651
1996-04-01	17.747
1996-07-01	22.464
1996-10-01	25.274
1997-01-01	28.340
1997-04-01	32.375
1997-07-01	38.748
1997-10-01	39.365
1998-01-01	40.246
1998-04-01	44.384
1998-07-01	46.178
1998-10-01	46.056
1999-01-01	52.260
1999-04-01	53.705
1999-07-01	56.472
1999-10-01	58.888
2000-01-01	61.225
2000-04-01	66.973
2000-07-01	72.021
2000-10-01	76.613
2001-01-01	84.453
2001-04-01	91.503
2001-07-01	98.161
2001-10-01	102.613
2002-01-01	105.287
2002-04-01	108.852
2002-07-01	107.904
2002-10-01	113.168
2003-01-01	115.537
2003-04-01	119.468
2003-07-01	122.934
2003-10-01	133.651
2004-01-01	132.951
2004-04-01	136.741
2004-07-01	140.117
2004-10-01	150.936
2005-01-01	152.205
2005-04-01	158.190
2005-07-01	164.685
2005-10-01	169.277
2006-01-01	173.586
2006-04-01	185.740
2006-07-01	189.803
2006-10-01	198.336
2007-01-01	200.275
2007-04-01	212.165
2007-07-01	218.635
2007-10-01	221.149
2008-01-01	236.189
2008-04-01	234.156
2008-07-01	231.609
2008-10-01	226.403
2009-01-01	224.441
2009-04-01	240.689
2009-07-01	247.590
2009-10-01	251.611
2010-01-01	252.221
2010-04-01	246.983
2010-07-01	259.170
2010-10-01	260.932
2011-01-01	254.922
2011-04-01	260.122
2011-07-01	255.024
2011-10-01	258.363
2012-01-01	276.972
2012-04-01	284.361
2012-07-01	300.185
2012-10-01	314.148
2013-01-01	318.013
2013-04-01	324.216
2013-07-01	327.994
2013-10-01	325.765
2014-01-01	330.129
2014-04-01	331.419
2014-07-01	336.071
2014-10-01	333.457
2015-01-01	338.424
2015-04-01	347.003