Year	Percent
1999-01-01	57.825
2000-01-01	56.400
2001-01-01	57.875
2002-01-01	57.850
2003-01-01	57.075
2004-01-01	61.525
2005-01-01	59.625
2006-01-01	55.925
2007-01-01	52.400
2008-01-01	50.125
2009-01-01	49.450
2010-01-01	48.625
2011-01-01	49.650
2012-01-01	47.750
2013-01-01	44.925
2014-01-01	43.200
2015-01-01	42.625
2016-01-01	38.850
2017-01-01	36.975