Year	Percent
1999-01-01	9.150
2000-01-01	7.950
2001-01-01	6.350
2002-01-01	7.000
2003-01-01	7.175
2004-01-01	7.025
2005-01-01	5.950
2006-01-01	5.375
2007-01-01	5.425
2008-01-01	8.900
2009-01-01	16.150
2010-01-01	17.925
2011-01-01	19.375
2012-01-01	23.025
2013-01-01	23.800
2014-01-01	21.675
2015-01-01	18.950
2016-01-01	16.350
2017-01-01	13.900