Year	%
1988	14.4
1991	10.84
1993	9.33
1996	6.27
1997	5.37
1998	5.23
1999	5.14
2000	4.81
2001	5.06
2002	4.2
2003	4.57
2004	5.37
2005	4.27
2006	3.68
2007	3.71
2008	3.89
2009	3.55
2010	3.12
2011	4.17
2012	4.41
2013	4.44
2014	1.28
2016	4.02
2020	3.6
2021	3.62