Year	Percent
1998-01-01	48.150
1999-01-01	47.725
2000-01-01	47.050
2001-01-01	46.475
2002-01-01	45.825
2003-01-01	45.400
2004-01-01	45.500
2005-01-01	44.700
2006-01-01	44.450
2007-01-01	44.050
2008-01-01	44.150
2009-01-01	44.325
2010-01-01	44.125
2011-01-01	45.350
2012-01-01	45.300
2013-01-01	45.875
2014-01-01	46.175
2015-01-01	46.275
2016-01-01	46.475
2017-01-01	45.925