Year	Percent
1999-01-01	32.725
2000-01-01	32.825
2001-01-01	32.350
2002-01-01	32.525
2003-01-01	32.850
2004-01-01	31.975
2005-01-01	32.275
2006-01-01	31.650
2007-01-01	32.175
2008-01-01	31.950
2009-01-01	32.350
2010-01-01	33.300
2011-01-01	33.500
2012-01-01	34.075
2013-01-01	34.650
2014-01-01	35.150
2015-01-01	35.325
2016-01-01	33.425
2017-01-01	34.625