Year	Percent
1999-01-01	17.650
2000-01-01	16.425
2001-01-01	17.825
2002-01-01	16.525
2003-01-01	17.325
2004-01-01	16.125
2005-01-01	15.875
2006-01-01	13.925
2007-01-01	10.150
2008-01-01	10.525
2009-01-01	13.650
2010-01-01	14.700
2011-01-01	15.750
2012-01-01	20.525
2013-01-01	21.650
2014-01-01	20.300
2015-01-01	16.425
2016-01-01	15.275
2017-01-01	11.275