Year	%
1988	20.88
1991	17.18
1993	13.55
1996	11.5
1997	10.2
1998	14.89
1999	10.66
2000	9.84
2001	9.2
2002	8.33
2003	9.46
2004	13.53
2005	7.32
2006	7.67
2007	8.19
2008	8.15
2009	8.59
2010	6.67
2011	6.25
2012	6.25
2013	6.26
2014	5.12
2016	5.78
2020	5.62
2021	5.61