Year	Percent
1999-01-01	6.200
2000-01-01	5.000
2001-01-01	5.600
2002-01-01	5.600
2003-01-01	8.500
2004-01-01	7.700
2005-01-01	8.800
2006-01-01	7.700
2007-01-01	7.100
2008-01-01	7.000
2009-01-01	8.500
2010-01-01	8.200
2011-01-01	7.700
2012-01-01	8.300
2013-01-01	8.725
2014-01-01	8.575
2015-01-01	8.775
2016-01-01	8.575
2017-01-01	8.050