Year	Percent
1998-01-01	35.825
1999-01-01	34.300
2000-01-01	33.525
2001-01-01	31.375
2002-01-01	29.150
2003-01-01	27.600
2004-01-01	25.375
2005-01-01	23.400
2006-01-01	23.700
2007-01-01	23.925
2008-01-01	23.500
2009-01-01	21.750
2010-01-01	20.600
2011-01-01	19.800
2012-01-01	21.000
2013-01-01	21.000
2014-01-01	21.625
2015-01-01	23.400
2016-01-01	23.225
2017-01-01	24.250