Year	Percent
1998-01-01	43.775
1999-01-01	42.750
2000-01-01	42.525
2001-01-01	40.625
2002-01-01	39.925
2003-01-01	39.250
2004-01-01	40.600
2005-01-01	38.825
2006-01-01	37.625
2007-01-01	36.000
2008-01-01	35.725
2009-01-01	33.775
2010-01-01	32.800
2011-01-01	31.200
2012-01-01	32.875
2013-01-01	30.700
2014-01-01	31.000
2015-01-01	30.475
2016-01-01	30.200
2017-01-01	29.975