Quarter	Billions of US Dollars
1966-01-01	0.015
1968-01-01	0.110
1968-04-01	0.145
1968-07-01	0.070
1968-10-01	0.028
1969-01-01	0.090
1969-10-01	0.008
1970-04-01	0.015
1970-10-01	0.020
1971-01-01	0.240
1971-04-01	0.095
1971-07-01	0.110
1971-10-01	0.270
1972-01-01	0.353
1972-04-01	0.500
1972-07-01	0.103
1972-10-01	0.257
1973-01-01	0.146
1973-04-01	0.025
1973-07-01	0.167
1973-10-01	0.125
1974-01-01	0.065
1974-04-01	0.010
1974-07-01	0.021
1974-10-01	0.042
1975-01-01	0.046
1975-04-01	0.157
1975-07-01	0.051
1975-10-01	0.104
1976-01-01	0.249
1976-04-01	0.055
1976-07-01	0.265
1976-10-01	0.311
1977-01-01	0.689
1977-04-01	0.608
1977-07-01	0.467
1977-10-01	0.689
1978-01-01	0.303
1978-04-01	0.100
1978-07-01	0.478
1978-10-01	0.454
1979-01-01	0.720
1979-04-01	0.948
1979-07-01	0.327
1979-10-01	0.590
1980-01-01	0.373
1980-04-01	1.580
1980-07-01	1.281
1980-10-01	1.397
1981-01-01	1.376
1981-04-01	1.165
1981-07-01	1.522
1981-10-01	2.040
1982-01-01	4.500
1982-04-01	4.431
1982-07-01	4.061
1982-10-01	3.229
1983-01-01	2.956
1983-04-01	2.392
1983-07-01	1.931
1983-10-01	3.227
1984-01-01	4.473
1984-04-01	3.467
1984-07-01	2.063
1984-10-01	2.590
1985-01-01	1.308
1985-04-01	1.627
1985-07-01	1.904
1985-10-01	3.158
1986-01-01	2.438
1986-04-01	4.091
1986-07-01	3.429
1986-10-01	3.743
1987-01-01	4.031
1987-04-01	3.233
1987-07-01	2.208
1987-10-01	2.670
1988-01-01	2.572
1988-04-01	3.282
1988-07-01	2.288
1988-10-01	2.957
1989-01-01	4.749
1989-04-01	2.540
1989-07-01	3.796
1989-10-01	3.346
1990-01-01	3.760
1990-04-01	2.761
1990-07-01	6.799
1990-10-01	2.743
1991-01-01	5.921
1991-04-01	3.373
1991-07-01	2.851
1991-10-01	3.048
1992-01-01	5.705
1992-04-01	2.916
1992-07-01	6.967
1992-10-01	2.257
1993-01-01	6.318
1993-04-01	4.429
1993-07-01	6.490
1993-10-01	11.742
1994-01-01	8.659
1994-04-01	8.447
1994-07-01	10.029
1994-10-01	10.767
1995-01-01	12.187
1995-04-01	12.384
1995-07-01	17.165
1995-10-01	11.781
1996-01-01	25.105
1996-04-01	19.455
1996-07-01	23.301
1996-10-01	30.788
1997-01-01	30.782
1997-04-01	24.473
1997-07-01	36.705
1997-10-01	29.218
1998-01-01	29.449
1998-04-01	30.128
1998-07-01	22.060
1998-10-01	17.885
1999-01-01	33.593
1999-04-01	27.545
1999-07-01	28.698
1999-10-01	26.614
2000-01-01	36.210
2000-04-01	29.144
2000-07-01	43.001
2000-10-01	34.692
2001-01-01	55.228
2001-04-01	51.370
2001-07-01	34.809
2001-10-01	40.605
2002-01-01	38.012
2002-04-01	38.579
2002-07-01	27.688
2002-10-01	30.243
2003-01-01	33.164
2003-04-01	34.965
2003-07-01	36.453
2003-10-01	41.352
2004-01-01	37.951
2004-04-01	40.224
2004-07-01	43.831
2004-10-01	49.395
2005-01-01	48.623
2005-04-01	47.051
2005-07-01	59.372
2005-10-01	90.561
2006-01-01	90.677
2006-04-01	103.326
2006-07-01	119.804
2006-10-01	156.657
2007-01-01	148.433
2007-04-01	180.056
2007-07-01	80.370
2007-10-01	55.863
2008-01-01	42.137
2008-04-01	48.987
2008-07-01	34.672
2008-10-01	19.217
2009-01-01	30.499
2009-04-01	39.655
2009-07-01	34.282
2009-10-01	37.069
2010-01-01	34.162
2010-04-01	27.362
2010-07-01	46.552
2010-10-01	45.340
2011-01-01	50.566
2011-04-01	48.048
2011-07-01	29.372
2011-10-01	42.468
2012-01-01	80.423
2012-04-01	56.603
2012-07-01	53.486
2012-10-01	75.795
2013-01-01	58.837
2013-04-01	82.640
2013-07-01	45.792
2013-10-01	62.847
2014-01-01	60.578
2014-04-01	107.134
2014-07-01	73.115
2014-10-01	65.757
2015-01-01	72.200
2015-04-01	79.828