Year	Percent
1998-01-01	58.500
1999-01-01	59.350
2000-01-01	63.750
2001-01-01	67.600
2002-01-01	66.800
2003-01-01	77.700
2004-01-01	80.100
2005-01-01	73.300
2006-01-01	56.700
2007-01-01	51.300
2008-01-01	47.350
2009-01-01	41.300
2010-01-01	41.980
2011-01-01	42.865
2012-01-01	45.490
2013-01-01	47.100
2014-01-01	48.545
2015-01-01	47.645