Year	Percent
1998-01-01	9.7
1999-01-01	9.7
2000-01-01	8.3
2001-01-01	9.3
2002-01-01	8.7
2003-01-01	8.3
2004-01-01	8.5
2005-01-01	8.2
2006-01-01	8.2
2007-01-01	8.2
2008-01-01	7.1
2009-01-01	7.6
2010-01-01	8.2
2011-01-01	9.1
2012-01-01	9.1