Year	Percent
1999-01-01	57.700
2000-01-01	58.400
2001-01-01	58.825
2002-01-01	58.600
2003-01-01	57.650
2004-01-01	60.450
2005-01-01	61.350
2006-01-01	61.850
2007-01-01	62.600
2008-01-01	64.225
2009-01-01	63.850
2010-01-01	62.575
2011-01-01	60.900
2012-01-01	60.525
2013-01-01	59.200
2014-01-01	60.000
2015-01-01	61.025
2016-01-01	62.625
2017-01-01	65.825