Year	%
1989	31.92
1990	18.95
1991	16.55
1992	15.71
1993	13.02
1994	13.27
1995	12.69
1996	14.83
1997	14
1998	15.94
1999	13.85
2000	12.69
2001	10.47
2002	10.01
2003	9.53
2004	9.06
2005	8.54
2006	8.46
2007	8.58
2008	8.58
2009	9.92
2010	10.09
2011	10.1
2012	10.12
2013	10.08
2014	9.92
2015	10.32
2016	10.19
2017	10.87
2018	10.99
2019	10.82
2020	10.25
2021	9.61