Quarter	Millions of US Dollars
1975-04-01	16
1977-07-01	43
1978-01-01	72
1978-04-01	68
1978-10-01	81
1979-04-01	149
1979-07-01	47
1979-10-01	87
1980-07-01	140
1982-04-01	-16
1984-04-01	-66
1984-07-01	-34
1985-01-01	-46
1985-10-01	-62
1986-04-01	-62
1986-10-01	-57
1987-04-01	-33
1987-07-01	-16
1988-01-01	-18
1988-10-01	-20
1989-04-01	-23
1989-07-01	-39
1989-10-01	-112
1990-07-01	-168
1991-10-01	500
1992-10-01	250
1993-04-01	17447
1993-07-01	215
1993-10-01	9821
1994-01-01	350
1994-04-01	-131
1994-07-01	678
1994-10-01	1377
1995-01-01	-146
1995-04-01	1916
1995-07-01	1789
1995-10-01	1929
1996-01-01	2396
1996-04-01	2997
1996-07-01	1132
1996-10-01	3194
1997-01-01	4349
1997-04-01	934
1997-07-01	3935
1997-10-01	777
1998-01-01	2539
1998-04-01	3762
1998-07-01	2497
1998-10-01	-5866
1999-01-01	1820
1999-04-01	3645
1999-07-01	1543
1999-10-01	3282
2000-01-01	4790
2000-04-01	3458
2000-07-01	2343
2000-10-01	-333
2001-01-01	1459
2001-04-01	5484
2001-07-01	-488
2001-10-01	93
2002-01-01	-9
2002-04-01	-3
2002-07-01	-6
2003-01-01	-414
2003-07-01	-112
2004-01-01	0
2004-04-01	-2196
2004-07-01	-702
2004-10-01	0
2005-01-01	0
2005-04-01	-29788
2005-07-01	-77
2005-10-01	-341
2006-04-01	-460
2006-07-01	-191
2006-10-01	101
2007-01-01	-444
2007-04-01	-45
2007-07-01	-478
2007-10-01	-301
2008-01-01	-1402
2008-04-01	-604
2008-07-01	-198
2008-10-01	-6373
2009-01-01	-345
2009-04-01	-775
2009-10-01	-266
2010-01-01	-289
2010-04-01	1236
2010-07-01	177
2010-10-01	520
2011-01-01	750
2011-04-01	-360
2011-07-01	-643
2011-10-01	85
2012-01-01	-120
2012-07-01	108
2012-10-01	-85
2013-01-01	0
2014-04-01	-42
2014-07-01	-72
2014-10-01	-549
2015-01-01	1037
2015-04-01	-726
2015-07-01	11
2015-10-01	-1040
2016-01-01	1260
2016-04-01	19588
2016-07-01	3926
2016-10-01	3956
2017-01-01	10502
2017-04-01	12602
2017-07-01	651
2017-10-01	3757
2018-01-01	9011
2018-04-01	-2580