Year	Percent
2000-01-01	21.675
2001-01-01	21.075
2002-01-01	20.925
2003-01-01	20.900
2004-01-01	20.100
2005-01-01	19.075
2006-01-01	18.600
2007-01-01	17.900
2008-01-01	18.050
2009-01-01	18.800
2010-01-01	19.325
2011-01-01	19.550
2012-01-01	19.300
2013-01-01	18.650
2014-01-01	18.275
2015-01-01	18.100
2016-01-01	18.100
2017-01-01	17.200