Year	Percent
1998-01-01	7.600
1999-01-01	7.900
2000-01-01	8.550
2001-01-01	8.800
2002-01-01	8.950
2003-01-01	8.600
2004-01-01	8.600
2005-01-01	8.500
2006-01-01	9.250
2007-01-01	9.000
2008-01-01	9.000
2009-01-01	9.200
2010-01-01	9.390
2011-01-01	9.800
2012-01-01	9.955
2013-01-01	9.575
2014-01-01	9.950
2015-01-01	10.310