Year	%
1988	14.65
1991	11.26
1993	9.73
1996	6.27
1997	6.23
1998	5.23
1999	5.14
2000	4.81
2001	5.51
2002	4.7
2003	5.29
2004	5.37
2005	4.27
2006	4.36
2007	4.83
2008	5.06
2009	5.19
2010	4.37
2011	4.17
2012	4.41
2013	4.44
2014	3.52
2016	4.02
2020	3.6
2021	3.62