Year	Percent
1995-01-01	6
1996-01-01	13
1997-01-01	18
1998-01-01	23
1999-01-01	28
2000-01-01	32
2001-01-01	34
2002-01-01	34
2003-01-01	26
2004-01-01	29
2005-01-01	33
2006-01-01	37
2007-01-01	46
2008-01-01	46
2009-01-01	44
2010-01-01	44
2011-01-01	48
2012-01-01	50
2013-01-01	52