Year	%
1991	6.22
1992	10.46
1994	11.53
1995	11.98
1996	10.87
1997	11.05
1998	10.74
1999	10.02
2000	10.54
2001	10.32
2002	10.87
2003	10.63
2004	9.62
2005	9.59
2006	8.88
2007	8.89
2008	8.75
2009	8.32
2010	9.12
2011	5.55
2012	4.58
2013	4.58
2014	4.32
2015	5.95
2016	6.35
2017	4.47
2018	3.3
2019	2.95
2020	2.44
2021	2.65