Year	Percent
1999-01-01	36.425
2000-01-01	36.475
2001-01-01	36.250
2002-01-01	35.700
2003-01-01	35.150
2004-01-01	36.750
2005-01-01	36.025
2006-01-01	35.425
2007-01-01	34.475
2008-01-01	34.200
2009-01-01	33.925
2010-01-01	33.950
2011-01-01	33.800
2012-01-01	33.550
2013-01-01	33.350
2014-01-01	33.475
2015-01-01	33.100
2016-01-01	32.350
2017-01-01	32.075