Year	Percent
1998-01-01	47.975
1999-01-01	47.525
2000-01-01	47.125
2001-01-01	46.675
2002-01-01	46.275
2003-01-01	45.925
2004-01-01	45.000
2005-01-01	45.400
2006-01-01	45.225
2007-01-01	45.450
2008-01-01	44.950
2009-01-01	45.525
2010-01-01	45.700
2011-01-01	45.600
2012-01-01	44.450
2013-01-01	44.650
2014-01-01	44.225
2015-01-01	44.125
2016-01-01	43.400
2017-01-01	42.900