Year	Percent
1998-01-01	42.600
1999-01-01	42.700
2000-01-01	42.225
2001-01-01	42.900
2002-01-01	42.125
2003-01-01	38.625
2004-01-01	36.525
2005-01-01	35.275
2006-01-01	34.775
2007-01-01	34.400
2008-01-01	34.075
2009-01-01	30.850
2010-01-01	27.875
2011-01-01	26.575
2012-01-01	23.025
2013-01-01	21.675
2014-01-01	22.375
2015-01-01	22.800
2016-01-01	23.900
2017-01-01	25.875