Year	Percent
1999-01-01	32.225
2000-01-01	29.700
2001-01-01	26.775
2002-01-01	26.500
2003-01-01	24.300
2004-01-01	28.575
2005-01-01	29.825
2006-01-01	30.300
2007-01-01	31.500
2008-01-01	33.200
2009-01-01	30.975
2010-01-01	30.000
2011-01-01	26.875
2012-01-01	23.725
2013-01-01	23.050
2014-01-01	23.975
2015-01-01	27.075
2016-01-01	26.050
2017-01-01	30.400