Year	%
1988	17.14
1989	13.72
1990	11.51
1992	9.9
1995	7.43
1996	7.71
1997	7.22
1998	6.59
1999	6.26
2000	4.98
2001	5.25
2002	5.07
2003	4.94
2004	4.56
2005	4.46
2006	4.52
2007	4.34
2008	4.25
2009	4.46
2010	4.46
2011	4.61
2012	4.77
2013	4.87
2014	4.86
2015	4.8
2016	4.87
2017	6.24
2018	6.24
2020	6.36
2021	4.1