Year	%
1988	22.26
1991	16.75
1993	13.37
1996	11.04
1997	9.9
1998	15.45
1999	10.43
2000	9.75
2001	9.75
2002	9.73
2003	10.07
2004	10.8
2005	8.74
2006	8.58
2007	8.58
2008	8.61
2009	8.99
2010	6.57
2011	6.55
2012	6.52
2013	6.35
2014	6.11
2016	6.18
2020	6.09
2021	6.06