Year	Percent
1998-01-01	44.900
1999-01-01	43.825
2000-01-01	45.500
2001-01-01	45.025
2002-01-01	40.750
2003-01-01	40.075
2004-01-01	39.825
2005-01-01	37.850
2006-01-01	37.250
2007-01-01	37.525
2008-01-01	35.850
2009-01-01	36.850
2010-01-01	37.550
2011-01-01	37.400
2012-01-01	35.975
2013-01-01	33.925
2014-01-01	32.075
2015-01-01	31.725
2016-01-01	29.050
2017-01-01	26.825