Year	Percent
1995-01-01	8
1996-01-01	8
1997-01-01	21
1998-01-01	27
1999-01-01	31
2000-01-01	31
2001-01-01	31
2002-01-01	31
2003-01-01	31
2004-01-01	31
2005-01-01	31
2006-01-01	38
2007-01-01	41
2008-01-01	41
2009-01-01	44
2010-01-01	44
2011-01-01	44
2012-01-01	50
2013-01-01	50