Year	Percent
1995-01-01	13.2
1996-01-01	13.4
1997-01-01	13.0
1998-01-01	12.5
1999-01-01	12.1
2000-01-01	11.3
2001-01-01	11.6
2002-01-01	12.5
2003-01-01	13.0
2004-01-01	13.0
2005-01-01	12.7
2006-01-01	12.1
2007-01-01	11.7
2008-01-01	12.7
2009-01-01	16.5
2010-01-01	17.0
2011-01-01	16.3
2012-01-01	16.1
2013-01-01	15.7
2014-01-01	14.2
2015-01-01	12.8
2016-01-01	11.8