Quarter	Millions of US Dollars
1973-07-01	5
1977-10-01	10
1982-01-01	16
1983-01-01	21
1985-10-01	56
1987-07-01	0
1988-01-01	-20
1988-10-01	0
1989-10-01	-8
1991-04-01	130
1993-01-01	34
1993-04-01	35
1993-07-01	-6
1993-10-01	34
1994-04-01	-60
1994-07-01	51
1995-01-01	10
1998-07-01	43
1998-10-01	25
1999-01-01	-8
1999-04-01	159
1999-07-01	-43
1999-10-01	29
2000-01-01	83
2000-04-01	-30
2000-07-01	76
2000-10-01	-27
2001-01-01	74
2001-04-01	-88
2001-07-01	9
2001-10-01	50
2002-04-01	75
2002-07-01	-5
2003-01-01	-15
2003-04-01	122
2003-07-01	-9
2003-10-01	0
2004-01-01	183
2004-04-01	10
2004-07-01	16
2004-10-01	26
2005-01-01	-10
2005-04-01	-10
2005-10-01	-5
2006-01-01	76
2006-04-01	-31
2006-07-01	287
2007-04-01	291
2007-10-01	75
2008-01-01	206
2008-04-01	-220
2008-07-01	134
2008-10-01	-20
2009-01-01	-59
2009-07-01	-61
2009-10-01	18
2010-01-01	-67
2010-04-01	-1
2010-07-01	10
2010-10-01	65
2011-01-01	-147
2011-04-01	36
2011-07-01	4
2011-10-01	-50
2012-04-01	-25
2012-07-01	0
2012-10-01	-43
2013-01-01	-52
2013-07-01	7
2013-10-01	24
2014-01-01	5
2014-04-01	-43
2014-07-01	-31
2014-10-01	-75
2015-01-01	30
2015-04-01	-90
2015-07-01	-150
2015-10-01	62
2016-01-01	0
2016-04-01	-40
2016-07-01	-92
2016-10-01	150
2017-01-01	0
2017-04-01	-218
2017-07-01	0
2017-10-01	0
2018-01-01	0
2018-04-01	-131