Year	Percent
1995-01-01	4
1996-01-01	4
1997-01-01	9
1998-01-01	12
1999-01-01	14
2000-01-01	16
2001-01-01	18
2002-01-01	20
2003-01-01	19
2004-01-01	23
2005-01-01	28
2006-01-01	34
2007-01-01	42
2008-01-01	48
2009-01-01	50
2010-01-01	52
2011-01-01	51
2012-01-01	44
2013-01-01	39