Year	Percent
1994-01-01	13.7
1995-01-01	13.1
1996-01-01	11.3
1997-01-01	11.8
1998-01-01	12.6
1999-01-01	16.3
2000-01-01	18.7
2001-01-01	19.3
2002-01-01	18.7
2003-01-01	17.6
2004-01-01	18.2
2005-01-01	16.2
2006-01-01	13.3
2007-01-01	11.2
2008-01-01	9.5
2009-01-01	12.0
2010-01-01	14.4
2011-01-01	13.6