Quarter	Millions of US Dollars
1971-01-01	30
1971-04-01	35
1971-10-01	25
1972-01-01	75
1972-04-01	32
1972-07-01	101
1972-10-01	41
1974-04-01	17
1974-07-01	75
1974-10-01	25
1975-01-01	209
1975-04-01	271
1975-10-01	88
1976-01-01	93
1976-04-01	283
1976-07-01	400
1976-10-01	280
1977-01-01	68
1977-04-01	61
1977-07-01	435
1977-10-01	356
1978-01-01	584
1978-04-01	250
1978-07-01	371
1978-10-01	261
1979-01-01	268
1979-04-01	51
1979-07-01	13
1979-10-01	154
1980-01-01	225
1980-04-01	-105
1980-07-01	23
1980-10-01	30
1981-01-01	90
1981-04-01	53
1981-07-01	82
1981-10-01	327
1982-01-01	58
1982-04-01	167
1982-07-01	830
1982-10-01	301
1983-01-01	221
1983-04-01	65
1983-07-01	493
1983-10-01	692
1984-01-01	721
1984-04-01	784
1984-07-01	507
1984-10-01	778
1985-01-01	794
1985-04-01	1045
1985-07-01	1437
1985-10-01	1333
1986-01-01	2076
1986-04-01	1583
1986-07-01	1216
1986-10-01	2607
1987-01-01	1228
1987-04-01	1515
1987-07-01	1308
1987-10-01	262
1988-01-01	615
1988-04-01	1075
1988-07-01	1283
1988-10-01	2067
1989-01-01	2604
1989-04-01	1142
1989-07-01	1294
1989-10-01	-449
1990-01-01	174
1990-04-01	-229
1990-07-01	567
1990-10-01	-673
1991-01-01	-432
1991-04-01	-1020
1991-07-01	264
1991-10-01	-650
1992-01-01	-335
1992-04-01	-1558
1992-07-01	-1201
1992-10-01	-826
1993-01-01	-1180
1993-04-01	-349
1993-07-01	13793
1993-10-01	102
1994-01-01	1735
1994-04-01	-874
1994-07-01	975
1994-10-01	2574
1995-01-01	2802
1995-04-01	-1002
1995-07-01	3387
1995-10-01	1852
1996-01-01	-273
1996-04-01	1842
1996-07-01	3111
1996-10-01	3871
1997-01-01	3031
1997-04-01	3153
1997-07-01	-983
1997-10-01	-4046
1998-01-01	1915
1998-04-01	607
1998-07-01	1347
1998-10-01	-964
1999-01-01	3052
1999-04-01	-451
1999-07-01	5345
1999-10-01	1414
2000-01-01	6387
2000-04-01	5527
2000-07-01	3509
2000-10-01	1627
2001-01-01	-607
2001-04-01	5635
2001-07-01	3850
2001-10-01	-2548
2002-01-01	3311
2002-04-01	1645
2002-07-01	5784
2002-10-01	5541
2003-01-01	3681
2003-04-01	11421
2003-07-01	11795
2003-10-01	11175
2004-01-01	16505
2004-04-01	7264
2004-07-01	22675
2004-10-01	9841
2005-01-01	11867
2005-04-01	20404
2005-07-01	-2645
2005-10-01	17000
2006-01-01	25327
2006-04-01	17574
2006-07-01	16156
2006-10-01	26051
2007-01-01	22507
2007-04-01	26512
2007-07-01	15524
2007-10-01	-2711
2008-01-01	41694
2008-04-01	-5586
2008-07-01	-7290
2008-10-01	-15367
2009-01-01	-9926
2009-04-01	15298
2009-07-01	14536
2009-10-01	35800
2010-01-01	13334
2010-04-01	30
2010-07-01	11307
2010-10-01	12725
2011-01-01	-332
2011-04-01	14581
2011-07-01	-2286
2011-10-01	-6088
2012-01-01	12550
2012-04-01	-2320
2012-07-01	37112
2012-10-01	-2417
2013-01-01	5584
2013-04-01	401
2013-07-01	8867
2013-10-01	21282
2014-01-01	956
2014-04-01	6799
2014-07-01	1778
2014-10-01	3234
2015-01-01	9040
2015-04-01	8247
2015-07-01	-13506
2015-10-01	13895
2016-01-01	10701
2016-04-01	14388
2016-07-01	11358
2016-10-01	-9698
2017-01-01	715
2017-04-01	3620
2017-07-01	10864
2017-10-01	-3529
2018-01-01	10175
2018-04-01	-2876