Year	Percent
1998-01-01	21.975
1999-01-01	21.925
2000-01-01	22.375
2001-01-01	21.800
2002-01-01	21.600
2003-01-01	19.900
2004-01-01	21.525
2005-01-01	20.025
2006-01-01	18.800
2007-01-01	18.825
2008-01-01	18.725
2009-01-01	18.300
2010-01-01	16.175
2011-01-01	12.850
2012-01-01	9.975
2013-01-01	9.125
2014-01-01	10.925
2015-01-01	10.925
2016-01-01	11.300
2017-01-01	12.400