Year	%
1988	17.98
1990	11.83
1991	11.49
1993	18.63
1996	16.15
1997	11.06
1999	10.2
2000	8.81
2001	9.08
2002	7.94
2003	7.94
2004	8.55
2005	8.54
2006	8.51
2007	8.25
2008	8.24
2009	8.24
2010	8.13
2011	8.13
2012	8.1
2013	8.11
2014	8.11
2015	8.12
2016	8.19
2017	8.4
2018	8.46
2019	10
2020	8.43
2021	8.44