Year	Percent
1995-01-01	17
1996-01-01	16
1997-01-01	15
1998-01-01	16
1999-01-01	15
2000-01-01	13
2001-01-01	15
2002-01-01	16
2003-01-01	17
2004-01-01	17
2005-01-01	21
2006-01-01	22
2007-01-01	22
2008-01-01	23
2009-01-01	23
2010-01-01	24
2011-01-01	24
2012-01-01	24
2013-01-01	24