Year	%
1988	18.68
1989	14.82
1990	12.7
1992	10.81
1995	7.76
1996	8.6
1997	8.55
1998	8.89
1999	8.09
2000	8.56
2001	8.41
2002	8.17
2003	7.94
2004	7.49
2005	7.5
2006	7.49
2007	7.48
2008	7.48
2009	7.4
2010	7.43
2011	7.41
2012	7.39
2013	7.38
2014	7.39
2015	7.39
2016	7.38
2017	7.5
2018	7.49
2020	7.49
2021	7.15