Year	Percent
1992-01-01	9.9
1993-01-01	12.1
1994-01-01	11.0
1995-01-01	10.4
1996-01-01	9.6
1997-01-01	9.0
1998-01-01	8.4
1999-01-01	6.9
2000-01-01	6.4
2001-01-01	5.7
2002-01-01	5.8
2003-01-01	5.9
2004-01-01	6.1
2005-01-01	7.2
2006-01-01	7.5
2007-01-01	7.4
2008-01-01	7.8
2009-01-01	10.0
2010-01-01	11.2
2011-01-01	10.9