Year	Percent
1999-01-01	21.175
2000-01-01	18.825
2001-01-01	13.700
2002-01-01	14.825
2003-01-01	14.675
2004-01-01	13.600
2005-01-01	10.675
2006-01-01	10.300
2007-01-01	9.500
2008-01-01	11.575
2009-01-01	16.575
2010-01-01	18.925
2011-01-01	20.500
2012-01-01	23.525
2013-01-01	25.225
2014-01-01	24.050
2015-01-01	22.400
2016-01-01	20.325
2017-01-01	18.175