Year	Percent
1998-01-01	56.9200
1999-01-01	57.3697
2000-01-01	59.9000
2001-01-01	58.6000
2002-01-01	56.1147
2003-01-01	48.0322
2004-01-01	55.4918
2005-01-01	54.4037
2006-01-01	51.7101
2007-01-01	52.3973
2008-01-01	55.8408
2009-01-01	51.8843
2010-01-01	53.3498
2011-01-01	54.9735
2012-01-01	56.1527
2013-01-01	54.2744
2014-01-01	54.8882
2015-01-01	54.1092
2016-01-01	55.6814