Year	Percent
1995-01-01	12
1996-01-01	13
1997-01-01	10
1998-01-01	9
1999-01-01	9
2000-01-01	8
2001-01-01	8
2002-01-01	7
2003-01-01	7
2004-01-01	6
2005-01-01	6
2006-01-01	6
2007-01-01	15
2008-01-01	18
2009-01-01	19
2010-01-01	21
2011-01-01	21
2012-01-01	20
2013-01-01	20