Year	Percent
1998-01-01	33.850
1999-01-01	32.850
2000-01-01	31.150
2001-01-01	28.200
2002-01-01	27.225
2003-01-01	27.075
2004-01-01	23.500
2005-01-01	24.100
2006-01-01	21.750
2007-01-01	20.375
2008-01-01	21.225
2009-01-01	25.325
2010-01-01	27.875
2011-01-01	29.075
2012-01-01	35.300
2013-01-01	40.000
2014-01-01	42.675
2015-01-01	40.325
2016-01-01	37.750
2017-01-01	34.750