Year	Percent
1999-01-01	33.825
2000-01-01	36.950
2001-01-01	39.175
2002-01-01	37.675
2003-01-01	33.400
2004-01-01	33.075
2005-01-01	30.050
2006-01-01	26.650
2007-01-01	20.325
2008-01-01	19.025
2009-01-01	27.175
2010-01-01	33.500
2011-01-01	33.425
2012-01-01	33.975
2013-01-01	33.675
2014-01-01	29.700
2015-01-01	26.450
2016-01-01	22.225
2017-01-01	18.900