Year	Percent
1999-01-01	36.225
2000-01-01	38.200
2001-01-01	40.200
2002-01-01	40.075
2003-01-01	40.200
2004-01-01	40.950
2005-01-01	43.775
2006-01-01	44.350
2007-01-01	44.225
2008-01-01	39.325
2009-01-01	29.375
2010-01-01	25.575
2011-01-01	22.075
2012-01-01	18.525
2013-01-01	17.350
2014-01-01	17.425
2015-01-01	18.575
2016-01-01	19.450
2017-01-01	21.200