Quarter	Billions of US Dollars
1971-01-01	0.043
1971-04-01	0.072
1971-07-01	0.105
1971-10-01	0.107
1972-01-01	0.110
1972-04-01	0.142
1972-07-01	0.140
1972-10-01	0.140
1973-01-01	0.156
1973-04-01	0.196
1973-07-01	0.239
1973-10-01	0.250
1974-01-01	0.296
1974-04-01	0.385
1974-07-01	0.378
1974-10-01	0.581
1975-01-01	1.004
1975-04-01	1.410
1975-07-01	1.553
1975-10-01	2.032
1976-01-01	2.831
1976-04-01	3.567
1976-07-01	3.839
1976-10-01	4.278
1977-01-01	4.833
1977-04-01	5.458
1977-07-01	5.948
1977-10-01	6.687
1978-01-01	7.365
1978-04-01	7.980
1978-07-01	9.460
1978-10-01	10.268
1979-01-01	11.350
1979-04-01	12.657
1979-07-01	14.231
1979-10-01	14.446
1980-01-01	13.526
1980-04-01	15.052
1980-07-01	15.680
1980-10-01	16.015
1981-01-01	15.635
1981-04-01	15.486
1981-07-01	17.432
1981-10-01	19.191
1982-01-01	19.510
1982-04-01	19.531
1982-07-01	20.319
1982-10-01	22.858
1983-01-01	24.770
1983-04-01	27.317
1983-07-01	28.788
1983-10-01	31.102
1984-01-01	35.438
1984-04-01	36.729
1984-07-01	38.449
1984-10-01	40.228
1985-01-01	45.175
1985-04-01	48.994
1985-07-01	57.636
1985-10-01	63.355
1986-01-01	69.705
1986-04-01	80.200
1986-07-01	90.710
1986-10-01	99.161
1987-01-01	110.375
1987-04-01	120.246
1987-07-01	134.347
1987-10-01	150.807
1988-01-01	152.513
1988-04-01	154.350
1988-07-01	168.717
1988-10-01	180.651
1989-01-01	194.018
1989-04-01	221.862
1989-07-01	239.530
1989-10-01	262.640
1990-01-01	274.058
1990-04-01	278.328
1990-07-01	302.332
1990-10-01	314.839
1991-01-01	315.157
1991-04-01	321.074
1991-07-01	340.763
1991-10-01	358.847
1992-01-01	349.924
1992-04-01	359.666
1992-07-01	366.140
1992-10-01	352.106
1993-01-01	340.850
1993-04-01	326.863
1993-07-01	333.597
1993-10-01	322.125
1994-01-01	332.361
1994-04-01	338.143
1994-07-01	341.425
1994-10-01	333.912
1995-01-01	357.159
1995-04-01	365.620
1995-07-01	331.943
1995-10-01	328.520
1996-01-01	324.653
1996-04-01	322.179
1996-07-01	325.602
1996-10-01	317.128
1997-01-01	307.193
1997-04-01	317.923
1997-07-01	315.258
1997-10-01	295.342
1998-01-01	286.286
1998-04-01	271.710
1998-07-01	275.525
1998-10-01	296.467
1999-01-01	288.230
1999-04-01	289.432
1999-07-01	317.176
1999-10-01	315.045
2000-01-01	297.387
2000-04-01	296.906
2000-07-01	282.420
2000-10-01	267.106
2001-01-01	250.224
2001-04-01	250.294
2001-07-01	251.149
2001-10-01	236.809
2002-01-01	227.799
2002-04-01	245.523
2002-07-01	237.315
2002-10-01	230.866
2003-01-01	227.565
2003-04-01	227.821
2003-07-01	234.346
2003-10-01	249.000
2004-01-01	255.957
2004-04-01	259.083
2004-07-01	257.867
2004-10-01	272.761
2005-01-01	268.708
2005-04-01	257.457
2005-07-01	255.130
2005-10-01	249.033
2006-01-01	261.018
2006-04-01	276.308
2006-07-01	279.350
2006-10-01	291.118
2007-01-01	298.943
2007-04-01	301.364
2007-07-01	320.119
2007-10-01	330.768
2008-01-01	357.256
2008-04-01	354.209
2008-07-01	347.121
2008-10-01	363.208
2009-01-01	344.038
2009-04-01	344.303
2009-07-01	359.702
2009-10-01	352.371
2010-01-01	342.655
2010-04-01	329.673
2010-07-01	355.796
2010-10-01	356.841
2011-01-01	356.609
2011-04-01	349.013
2011-07-01	346.083
2011-10-01	336.916
2012-01-01	330.879
2012-04-01	327.173
2012-07-01	346.044
2012-10-01	330.154
2013-01-01	325.991
2013-04-01	325.141
2013-07-01	343.525
2013-10-01	344.114
2014-01-01	356.359
2014-04-01	365.044
2014-07-01	364.637
2014-10-01	358.610
2015-01-01	364.524
2015-04-01	369.275