Year	Percent
1999-01-01	35.275
2000-01-01	39.700
2001-01-01	42.075
2002-01-01	39.450
2003-01-01	34.800
2004-01-01	34.725
2005-01-01	31.000
2006-01-01	26.375
2007-01-01	20.450
2008-01-01	18.500
2009-01-01	27.700
2010-01-01	34.625
2011-01-01	33.200
2012-01-01	34.950
2013-01-01	34.900
2014-01-01	29.450
2015-01-01	25.775
2016-01-01	19.750
2017-01-01	18.125