Year	Percent
1999-01-01	54.700
2000-01-01	50.550
2001-01-01	49.725
2002-01-01	50.300
2003-01-01	49.775
2004-01-01	52.950
2005-01-01	54.100
2006-01-01	54.050
2007-01-01	56.025
2008-01-01	56.150
2009-01-01	56.200
2010-01-01	53.975
2011-01-01	54.825
2012-01-01	55.375
2013-01-01	55.300
2014-01-01	55.375
2015-01-01	54.150
2016-01-01	54.625
2017-01-01	53.725