Year	Percent
1999-01-01	30.975
2000-01-01	29.000
2001-01-01	27.700
2002-01-01	27.025
2003-01-01	27.350
2004-01-01	26.325
2005-01-01	25.625
2006-01-01	25.900
2007-01-01	27.550
2008-01-01	26.250
2009-01-01	22.825
2010-01-01	20.675
2011-01-01	20.025
2012-01-01	20.100
2013-01-01	20.400
2014-01-01	21.775
2015-01-01	23.325
2016-01-01	25.225
2017-01-01	26.925