Year	Percent
2005-01-01	22.200
2006-01-01	22.900
2007-01-01	21.600
2008-01-01	21.100
2009-01-01	20.500
2010-01-01	21.650
2011-01-01	20.725
2012-01-01	20.575
2013-01-01	20.025
2014-01-01	20.875
2015-01-01	19.800
2016-01-01	19.300
2017-01-01	17.975