Year	%
1997	17.41
2001	17.41
2002	17.41
2003	17.08
2004	17.08
2005	17.08
2006	17.08
2007	16.34
2008	16.34
2009	16.34
2010	16.34
2011	16.34
2013	17.22
2014	17.22
2015	17.22