Year	%
1989	48.29
1990	35.54
1991	29.02
1992	23.91
1993	15.85
1994	14.35
1995	14.36
1996	14.76
1997	14.41
1998	17.26
1999	17.01
2000	16.77
2001	15.13
2002	14.87
2003	14.48
2004	14.41
2005	13.46
2006	13.41
2007	13.32
2008	14.55
2009	15.08
2010	15.2
2011	15.2
2012	15.21
2013	15.2
2014	15.23
2015	15.21
2016	15.21
2017	15.24
2018	15.24
2019	15.21
2020	15.21
2021	15.14