Year	Percent
1998-01-01	13.200
1999-01-01	11.275
2000-01-01	11.800
2001-01-01	12.125
2002-01-01	13.950
2003-01-01	17.000
2004-01-01	17.725
2005-01-01	19.125
2006-01-01	18.475
2007-01-01	20.300
2008-01-01	20.275
2009-01-01	21.700
2010-01-01	24.050
2011-01-01	31.650
2012-01-01	39.250
2013-01-01	39.675
2014-01-01	35.400
2015-01-01	34.450
2016-01-01	28.750
2017-01-01	25.475