Year	%
1997	18.33
2001	18.33
2002	18.33
2003	18.33
2004	17.77
2005	17.77
2006	17.77
2007	16.99
2008	16.99
2009	16.99
2010	16.99
2011	16.99
2012	17.82
2013	17.82
2015	17.82
2016	17.82
2018	17.97
2020	17.97
2021	17.97