Year	Percent
1998-01-01	33.925
1999-01-01	33.975
2000-01-01	34.300
2001-01-01	32.625
2002-01-01	31.000
2003-01-01	29.850
2004-01-01	31.750
2005-01-01	28.750
2006-01-01	26.850
2007-01-01	25.450
2008-01-01	25.525
2009-01-01	23.675
2010-01-01	23.150
2011-01-01	22.775
2012-01-01	24.000
2013-01-01	23.400
2014-01-01	23.100
2015-01-01	21.675
2016-01-01	22.750
2017-01-01	22.100