Year	Percent
1998-01-01	58.2872
1999-01-01	59.7072
2000-01-01	56.4000
2001-01-01	48.3000
2002-01-01	49.3362
2003-01-01	43.2750
2004-01-01	50.3143
2005-01-01	58.5659
2006-01-01	56.8315
2007-01-01	51.8066
2008-01-01	38.0677
2009-01-01	55.7920
2010-01-01	65.3361
2011-01-01	56.4447
2012-01-01	52.6865
2013-01-01	44.9362
2014-01-01	51.8722
2015-01-01	41.5809
2016-01-01	41.4422