Year	Percent
1998-01-01	46.475
1999-01-01	48.600
2000-01-01	51.650
2001-01-01	54.850
2002-01-01	57.775
2003-01-01	60.400
2004-01-01	61.250
2005-01-01	61.150
2006-01-01	62.275
2007-01-01	63.275
2008-01-01	64.100
2009-01-01	62.750
2010-01-01	63.800
2011-01-01	64.525
2012-01-01	63.550
2013-01-01	63.225
2014-01-01	61.925
2015-01-01	62.625
2016-01-01	62.550
2017-01-01	63.550