Year	Percent
1999-01-01	39.350
2000-01-01	36.450
2001-01-01	33.675
2002-01-01	32.500
2003-01-01	30.300
2004-01-01	35.350
2005-01-01	36.275
2006-01-01	36.425
2007-01-01	35.425
2008-01-01	37.400
2009-01-01	35.750
2010-01-01	34.825
2011-01-01	32.300
2012-01-01	30.025
2013-01-01	30.175
2014-01-01	30.425
2015-01-01	31.675
2016-01-01	30.550
2017-01-01	34.925