Year	Percent
1998-01-01	52.100
1999-01-01	47.150
2000-01-01	46.400
2001-01-01	46.700
2002-01-01	47.925
2003-01-01	48.650
2004-01-01	49.475
2005-01-01	49.100
2006-01-01	47.375
2007-01-01	46.775
2008-01-01	46.575
2009-01-01	50.325
2010-01-01	50.600
2011-01-01	49.525
2012-01-01	48.825
2013-01-01	49.250
2014-01-01	48.475
2015-01-01	48.950
2016-01-01	48.750
2017-01-01	47.675