Year	Percent
1995-01-01	5
1996-01-01	5
1997-01-01	9
1998-01-01	9
1999-01-01	14
2000-01-01	19
2001-01-01	14
2002-01-01	13
2003-01-01	12
2004-01-01	12
2005-01-01	16
2006-01-01	30
2007-01-01	35
2008-01-01	38
2009-01-01	38
2010-01-01	42
2011-01-01	43
2012-01-01	43
2013-01-01	43