Year	Percent
1998-01-01	29.075
1999-01-01	29.750
2000-01-01	30.600
2001-01-01	31.675
2002-01-01	32.275
2003-01-01	32.775
2004-01-01	34.475
2005-01-01	34.250
2006-01-01	34.850
2007-01-01	34.975
2008-01-01	35.400
2009-01-01	34.700
2010-01-01	34.500
2011-01-01	34.725
2012-01-01	35.025
2013-01-01	34.500
2014-01-01	34.575
2015-01-01	34.750
2016-01-01	35.275
2017-01-01	35.850