Year	Percent
1998-01-01	48.075
1999-01-01	47.925
2000-01-01	48.375
2001-01-01	48.775
2002-01-01	49.050
2003-01-01	49.200
2004-01-01	49.450
2005-01-01	49.325
2006-01-01	49.450
2007-01-01	50.225
2008-01-01	50.650
2009-01-01	50.475
2010-01-01	50.700
2011-01-01	50.525
2012-01-01	49.975
2013-01-01	49.100
2014-01-01	49.125
2015-01-01	48.750
2016-01-01	48.125
2017-01-01	47.725