Quarter	Millions of US Dollars
1997-01-01	16
1997-04-01	5
1998-04-01	1
1998-07-01	-1
1999-04-01	-1
2000-04-01	-5
2001-07-01	0
2001-10-01	0
2005-01-01	-16
2009-01-01	0
2016-10-01	550