Year	%
1997	22.93
1998	22.83
1999	22.83
2000	22.83
2001	22.83
2002	22.83
2003	22.83
2004	22.8
2005	22.78
2006	22.8
2007	22.8
2008	22.9
2009	22.9
2010	22.9
2011	22.9
2012	22.91
2013	22.91
2015	22.91
2020	22.96
2021	22.96