Year	Percent
1996-01-01	68.21
1997-01-01	66.34
1998-01-01	62.63
1999-01-01	66.65
2000-01-01	63.97
2001-01-01	65.18
2002-01-01	66.39
2003-01-01	64.22
2004-01-01	63.04
2005-01-01	60.71
2006-01-01	56.81
2007-01-01	53.78
2008-01-01	55.09
2009-01-01	55.05
2010-01-01	56.99
2011-01-01	58.15
2012-01-01	58.01
2013-01-01	60.31
2014-01-01	87.56
2015-01-01	85.37