Year	Percent
1999-01-01	35.075
2000-01-01	34.900
2001-01-01	35.800
2002-01-01	35.225
2003-01-01	35.075
2004-01-01	34.100
2005-01-01	33.250
2006-01-01	33.475
2007-01-01	32.925
2008-01-01	32.875
2009-01-01	33.075
2010-01-01	32.350
2011-01-01	33.300
2012-01-01	33.075
2013-01-01	32.450
2014-01-01	32.300
2015-01-01	32.425
2016-01-01	32.375
2017-01-01	31.975