Year	Percent
1999-01-01	29.000
2000-01-01	28.200
2001-01-01	26.575
2002-01-01	25.300
2003-01-01	25.400
2004-01-01	24.600
2005-01-01	23.075
2006-01-01	22.525
2007-01-01	24.125
2008-01-01	21.450
2009-01-01	18.675
2010-01-01	17.350
2011-01-01	15.025
2012-01-01	15.950
2013-01-01	16.200
2014-01-01	16.475
2015-01-01	18.025
2016-01-01	18.225
2017-01-01	21.150