Year	Percent
1998-01-01	9.8
1999-01-01	9.9
2000-01-01	9.8
2001-01-01	8.7
2002-01-01	8.5
2003-01-01	7.6
2004-01-01	7.6
2005-01-01	7.7
2006-01-01	7.4
2007-01-01	6.9
2008-01-01	6.9
2009-01-01	7.2
2010-01-01	8.3
2011-01-01	8.1
2012-01-01	8.5
2013-01-01	8.6
2014-01-01	8.9