Quarter	Millions of US Dollars
1978-01-01	20
1980-04-01	50
1980-07-01	12
1980-10-01	46
1985-01-01	-20
1985-04-01	-50
1985-10-01	-40
1990-04-01	565
1990-10-01	-15
1993-07-01	3087
1993-10-01	-383
1994-01-01	-15
1994-04-01	-1491
1994-07-01	-442
1994-10-01	58
1995-01-01	-1105
1995-04-01	-211
1995-07-01	216
1995-10-01	-589
1996-01-01	8
1996-04-01	50
1996-07-01	-176
1996-10-01	-160
1997-01-01	-152
1997-04-01	-151
1997-07-01	130
1997-10-01	-52
1998-01-01	-26
1998-04-01	138
1998-07-01	-41
1998-10-01	-73
1999-01-01	52
1999-04-01	386
1999-07-01	84
1999-10-01	25
2000-01-01	19
2000-04-01	-72
2000-07-01	142
2000-10-01	-27
2001-01-01	225
2001-04-01	-81
2001-07-01	-20
2001-10-01	0
2002-01-01	239
2002-04-01	-23
2002-07-01	-6
2002-10-01	-11
2003-01-01	454
2003-04-01	-356
2003-07-01	9
2003-10-01	44
2004-01-01	96
2004-04-01	8
2004-07-01	14
2004-10-01	-2
2005-01-01	-2
2005-04-01	-13
2005-07-01	-32
2005-10-01	-6
2006-01-01	-4
2006-04-01	0
2006-07-01	-1
2008-01-01	-200
2009-04-01	-300
2011-01-01	-250
2011-10-01	250
2012-01-01	-250
2012-04-01	250
2012-10-01	1000
2013-01-01	-250
2013-04-01	1500
2013-07-01	500
2013-10-01	960
2014-01-01	40
2014-04-01	1000
2015-01-01	1000
2015-10-01	127
2016-04-01	500
2017-04-01	600