Year	%
1988	18.88
1991	16.21
1993	12.96
1996	9.98
1997	8.07
1998	14.08
1999	9.3
2000	8.92
2001	8.12
2002	8.07
2003	7.92
2004	9.5
2005	8.3
2006	6.96
2007	6.4
2008	6.21
2009	6.08
2010	5.02
2011	6.27
2012	6.3
2013	6.12
2014	3.7
2016	5.83
2020	5.71
2021	5.62