Year	Percent
1998-01-01	54.850
1999-01-01	49.050
2000-01-01	47.725
2001-01-01	47.925
2002-01-01	48.550
2003-01-01	49.325
2004-01-01	50.275
2005-01-01	49.325
2006-01-01	48.175
2007-01-01	46.575
2008-01-01	46.525
2009-01-01	49.575
2010-01-01	50.650
2011-01-01	49.475
2012-01-01	48.425
2013-01-01	48.175
2014-01-01	47.925
2015-01-01	47.825
2016-01-01	47.800
2017-01-01	46.775