Quarter	Millions of US Dollars
1996-04-01	41
1997-01-01	18
1997-04-01	9
1997-07-01	68
1997-10-01	122
1998-01-01	-11
1998-04-01	19
1998-10-01	-7
1999-01-01	39
1999-04-01	-37
1999-07-01	11
1999-10-01	-22
2000-01-01	-15
2000-04-01	-20
2000-07-01	-12
2000-10-01	-2
2001-01-01	-7
2001-04-01	-21
2001-07-01	-2
2001-10-01	-15
2002-01-01	-44
2002-04-01	52
2002-07-01	198
2002-10-01	-4
2003-04-01	-4
2003-07-01	0
2003-10-01	-2
2004-04-01	33
2004-07-01	-12
2005-10-01	190
2006-01-01	-66
2007-04-01	-135
2007-10-01	38
2011-07-01	322
2012-04-01	395
2013-04-01	153
2014-01-01	135
2014-04-01	-39
2015-07-01	563
2015-10-01	-7
2018-04-01	274