Year	Percent
1999-01-01	36.850
2000-01-01	32.875
2001-01-01	26.875
2002-01-01	27.075
2003-01-01	26.925
2004-01-01	26.325
2005-01-01	23.425
2006-01-01	21.500
2007-01-01	21.725
2008-01-01	25.525
2009-01-01	36.100
2010-01-01	39.625
2011-01-01	44.025
2012-01-01	51.475
2013-01-01	54.625
2014-01-01	52.975
2015-01-01	48.000
2016-01-01	44.950
2017-01-01	37.525