Year	Percent
1998-01-01	73.3
1999-01-01	76.9
2000-01-01	76.9
2001-01-01	76.9
2002-01-01	76.9
2003-01-01	76.9
2004-01-01	76.9
2005-01-01	49.1
2006-01-01	50
2007-01-01	51.3
2008-01-01	48.3
2009-01-01	40.9
2010-01-01	32.7
2011-01-01	38.3
2012-01-01	36.4
2013-01-01	39.9