Year	Percent
1999-01-01	29.375
2000-01-01	26.000
2001-01-01	21.075
2002-01-01	22.200
2003-01-01	22.700
2004-01-01	22.000
2005-01-01	19.650
2006-01-01	17.900
2007-01-01	18.100
2008-01-01	24.475
2009-01-01	37.750
2010-01-01	41.500
2011-01-01	46.225
2012-01-01	52.875
2013-01-01	55.475
2014-01-01	53.200
2015-01-01	48.350
2016-01-01	44.450
2017-01-01	38.675