Year	Percent
1998-01-01	55.62920000000000
1999-01-01	54.49420000000000
2000-01-01	50.60000000000000
2001-01-01	53.70000000000000
2002-01-01	56.04350000000000
2003-01-01	58.48150000000000
2004-01-01	60.99060000000000
2005-01-01	62.92400000000000
2006-01-01	65.30199999999999
2007-01-01	59.03530000000000
2008-01-01	56.05750000000000
2009-01-01	56.20910000000000
2010-01-01	58.34480000000000
2011-01-01	56.39700000000000
2012-01-01	52.88330000000000
2013-01-01	50.31720000000000
2014-01-01	52.33840000000000
2015-01-01	55.66850000000000
2016-01-01	59.19820000000000