Year	Percent
1998-01-01	47.700
1999-01-01	46.675
2000-01-01	44.400
2001-01-01	41.525
2002-01-01	38.725
2003-01-01	36.775
2004-01-01	35.175
2005-01-01	34.000
2006-01-01	33.550
2007-01-01	31.950
2008-01-01	31.150
2009-01-01	31.850
2010-01-01	30.925
2011-01-01	29.950
2012-01-01	31.275
2013-01-01	31.550
2014-01-01	32.225
2015-01-01	32.500
2016-01-01	31.975
2017-01-01	31.650