Year	%
1991	15.92
1993	11.42
1996	7.64
1997	7.26
1998	6.9
1999	6.56
2000	6.15
2001	5.1
2002	5.11
2003	5.11
2004	5.11
2005	4.19
2006	4.21
2007	4.23
2008	4.21
2009	4.22
2010	3.32
2011	3.28
2012	3.3
2013	3.29
2014	3.29
2015	3.03
2016	3.03
2017	3.04
2018	3.04
2019	2.97
2020	2.97
2021	2.97