Year	Percent
1998-01-01	45.150
1999-01-01	50.950
2000-01-01	52.275
2001-01-01	52.075
2002-01-01	51.450
2003-01-01	50.675
2004-01-01	49.725
2005-01-01	50.675
2006-01-01	51.825
2007-01-01	53.425
2008-01-01	53.475
2009-01-01	50.425
2010-01-01	49.350
2011-01-01	50.525
2012-01-01	51.575
2013-01-01	51.825
2014-01-01	52.075
2015-01-01	52.175
2016-01-01	52.200
2017-01-01	53.225