Year	Percent
2001-01-01	22.150
2002-01-01	22.400
2003-01-01	22.675
2004-01-01	22.825
2005-01-01	21.775
2006-01-01	21.225
2007-01-01	20.850
2008-01-01	20.650
2009-01-01	21.075
2010-01-01	20.900
2011-01-01	20.075
2012-01-01	19.700
2013-01-01	18.900
2014-01-01	18.475
2015-01-01	18.250
2016-01-01	17.900
2017-01-01	17.475