Year	Percent
1998-01-01	6.500000000000000
1999-01-01	3.800000000000000
2000-01-01	3.800000000000000
2001-01-01	3.800000000000000
2002-01-01	3.800000000000000
2003-01-01	3.800000000000000
2004-01-01	3.800000000000000
2005-01-01	3.800000000000000
2006-01-01	3.800000000000000
2007-01-01	3.800000000000000
2008-01-01	3.800000000000000
2009-01-01	3.800000000000000
2010-01-01	18.183700000000000
2011-01-01	17.226200000000000
2012-01-01	17.190600000000000
2013-01-01	18.061600000000000
2014-01-01	17.029800000000000
2015-01-01	18.855999999999998
2016-01-01	19.149300000000000