Year	Percent
1993-01-01	14.0
1994-01-01	14.4
1995-01-01	13.3
1996-01-01	12.4
1997-01-01	10.9
1998-01-01	10.2
1999-01-01	13.4
2000-01-01	16.2
2001-01-01	18.3
2002-01-01	20.0
2003-01-01	19.7
2004-01-01	19.0
2005-01-01	17.8
2006-01-01	13.9
2007-01-01	9.7
2008-01-01	7.2
2009-01-01	8.2
2010-01-01	9.6
2011-01-01	9.7