Year	Percent
1995-01-01	13
1996-01-01	13
1997-01-01	12
1998-01-01	14
1999-01-01	15
2000-01-01	15
2001-01-01	14
2002-01-01	19
2003-01-01	20
2004-01-01	21
2005-01-01	23
2006-01-01	34
2007-01-01	39
2008-01-01	39
2009-01-01	39
2010-01-01	39
2011-01-01	36
2012-01-01	35
2013-01-01	38