Year	%
1994	19.92
1997	17.37
2001	19.01
2002	18.99
2003	19.28
2004	19.28
2005	19.41
2006	19.28
2007	17.83
2008	17.78
2009	17.78
2010	17.78
2011	17.78
2013	17.93
2014	17.87
2015	12.42