Year	Percent
1998-01-01	10.200
1999-01-01	9.400
2000-01-01	9.200
2001-01-01	8.600
2002-01-01	8.900
2003-01-01	9.000
2004-01-01	9.200
2005-01-01	8.925
2006-01-01	8.175
2007-01-01	7.150
2008-01-01	6.975
2009-01-01	8.900
2010-01-01	9.550
2011-01-01	9.625
2012-01-01	10.450
2013-01-01	10.825
2014-01-01	10.250
2015-01-01	9.450
2016-01-01	8.575
2017-01-01	7.625