Year	Percent
1999-01-01	32.125
2000-01-01	33.775
2001-01-01	35.700
2002-01-01	35.500
2003-01-01	31.700
2004-01-01	31.050
2005-01-01	28.775
2006-01-01	26.950
2007-01-01	20.200
2008-01-01	19.850
2009-01-01	26.350
2010-01-01	31.925
2011-01-01	33.800
2012-01-01	32.450
2013-01-01	31.625
2014-01-01	30.125
2015-01-01	27.500
2016-01-01	26.350
2017-01-01	20.175