Year	Percent
1998-01-01	55.425
1999-01-01	54.500
2000-01-01	53.700
2001-01-01	52.725
2002-01-01	52.100
2003-01-01	51.650
2004-01-01	49.200
2005-01-01	49.525
2006-01-01	49.200
2007-01-01	49.350
2008-01-01	48.350
2009-01-01	48.875
2010-01-01	48.925
2011-01-01	48.550
2012-01-01	46.575
2013-01-01	46.425
2014-01-01	45.600
2015-01-01	45.900
2016-01-01	44.800
2017-01-01	44.050