Year	Percent
1999-01-01	38.750
2000-01-01	37.300
2001-01-01	34.400
2002-01-01	31.200
2003-01-01	29.825
2004-01-01	26.300
2005-01-01	24.375
2006-01-01	24.575
2007-01-01	24.375
2008-01-01	23.300
2009-01-01	20.000
2010-01-01	19.900
2011-01-01	19.700
2012-01-01	19.800
2013-01-01	23.050
2014-01-01	26.425
2015-01-01	28.100
2016-01-01	31.475
2017-01-01	32.950