Year	Percent
1998-01-01	21.2000
1999-01-01	21.2000
2000-01-01	21.0000
2001-01-01	20.3000
2002-01-01	21.3000
2003-01-01	19.3000
2004-01-01	17.8000
2005-01-01	17.8000
2006-01-01	21.9000
2007-01-01	20.6000
2008-01-01	16.0000
2009-01-01	16.9000
2010-01-01	17.5987
2011-01-01	17.5502
2012-01-01	18.2311
2013-01-01	17.8723
2014-01-01	17.8768
2015-01-01	18.0780
2016-01-01	19.5447