Year	Percent
1999-01-01	16.50
2000-01-01	16.50
2001-01-01	15.60
2002-01-01	17.10
2003-01-01	17.60
2004-01-01	17.60
2005-01-01	18.50
2006-01-01	17.20
2007-01-01	15.80
2008-01-01	14.70
2009-01-01	15.60
2010-01-01	15.80
2011-01-01	15.90
2012-01-01	16.00
2013-01-01	16.20
2014-01-01	15.43
2015-01-01	16.20