Year	Percent
1999-01-01	22.925
2000-01-01	22.675
2001-01-01	22.925
2002-01-01	23.000
2003-01-01	22.175
2004-01-01	22.150
2005-01-01	21.275
2006-01-01	20.075
2007-01-01	19.850
2008-01-01	19.700
2009-01-01	19.725
2010-01-01	19.125
2011-01-01	18.750
2012-01-01	17.125
2013-01-01	16.700
2014-01-01	15.000
2015-01-01	14.200
2016-01-01	13.875
2017-01-01	13.175