Quarter	Millions of US Dollars
1973-07-01	27
1973-10-01	6
1975-01-01	24
1977-04-01	43
1977-07-01	21
1978-07-01	-48
1978-10-01	-12
1981-01-01	20
1981-07-01	60
1981-10-01	30
1982-07-01	73
1982-10-01	80
1983-01-01	100
1983-04-01	300
1983-07-01	117
1983-10-01	350
1984-01-01	386
1984-04-01	700
1984-07-01	137
1984-10-01	275
1985-01-01	506
1985-04-01	479
1985-07-01	936
1985-10-01	588
1986-01-01	122
1986-04-01	383
1986-07-01	464
1986-10-01	292
1987-01-01	209
1987-04-01	65
1987-07-01	-179
1987-10-01	1
1988-01-01	157
1988-04-01	-42
1988-07-01	127
1988-10-01	20
1989-01-01	577
1989-04-01	122
1989-07-01	-7
1989-10-01	-198
1990-01-01	257
1990-04-01	-453
1990-07-01	545
1990-10-01	-234
1991-01-01	590
1991-04-01	-100
1991-07-01	8
1991-10-01	-135
1992-01-01	-893
1992-04-01	-252
1992-07-01	-229
1992-10-01	-88
1993-01-01	-60
1993-04-01	-120
1993-07-01	172
1993-10-01	1720
1994-01-01	886
1994-04-01	539
1994-07-01	1077
1994-10-01	2392
1995-01-01	107
1995-04-01	417
1995-07-01	135
1995-10-01	2017
1996-01-01	-1161
1996-04-01	-1121
1996-07-01	1677
1996-10-01	1680
1997-01-01	1754
1997-04-01	2630
1997-07-01	997
1997-10-01	-399
1998-01-01	-328
1998-04-01	95
1998-07-01	375
1998-10-01	18
1999-01-01	3070
1999-04-01	-1120
1999-07-01	2552
1999-10-01	347
2000-01-01	-1455
2000-04-01	-1111
2000-07-01	986
2000-10-01	1627
2001-01-01	-213
2001-04-01	2558
2001-07-01	-461
2001-10-01	-945
2002-01-01	3723
2002-04-01	2488
2002-07-01	1174
2002-10-01	86
2003-01-01	732
2003-04-01	1391
2003-07-01	192
2003-10-01	120
2004-01-01	1038
2004-04-01	593
2004-07-01	1776
2004-10-01	375
2005-01-01	1648
2005-04-01	-41
2005-07-01	-486
2005-10-01	-3747
2006-01-01	584
2006-04-01	1221
2006-07-01	-444
2006-10-01	1087
2007-01-01	-629
2007-04-01	2024
2007-07-01	117
2007-10-01	-284
2008-01-01	159
2008-04-01	393
2008-07-01	1502
2008-10-01	945
2009-01-01	-2891
2009-04-01	1342
2009-07-01	520
2009-10-01	420
2010-01-01	3138
2010-04-01	1124
2010-07-01	4559
2010-10-01	5507
2011-01-01	1059
2011-04-01	15304
2011-07-01	4500
2011-10-01	5334
2012-01-01	13173
2012-04-01	6259
2012-07-01	7830
2012-10-01	3860
2013-01-01	10004
2013-04-01	15039
2013-07-01	3955
2013-10-01	9455
2014-01-01	11675
2014-04-01	15792
2014-07-01	14217
2014-10-01	1487
2015-01-01	8753
2015-04-01	3032
2015-07-01	-7854
2015-10-01	18750
2016-01-01	-6185
2016-04-01	-2401
2016-07-01	12060
2016-10-01	6324
2017-01-01	15718
2017-04-01	16114
2017-07-01	10316
2017-10-01	20111
2018-01-01	5354
2018-04-01	16529