Year	Percent
1998-01-01	48.475
1999-01-01	47.950
2000-01-01	47.500
2001-01-01	48.100
2002-01-01	46.550
2003-01-01	46.050
2004-01-01	46.825
2005-01-01	46.325
2006-01-01	46.575
2007-01-01	45.375
2008-01-01	45.725
2009-01-01	46.200
2010-01-01	45.700
2011-01-01	46.400
2012-01-01	46.675
2013-01-01	45.650
2014-01-01	44.725
2015-01-01	43.000
2016-01-01	41.525
2017-01-01	38.525