Year	%
1988	13.52
1990	11.63
1991	11.33
1993	16.41
1996	14.8
1997	10.72
1999	9.74
2000	9.45
2001	9.65
2002	8.3
2003	8.47
2004	9.3
2005	8.85
2006	8.46
2007	8.06
2008	7.62
2009	7.53
2010	7.31
2011	7.11
2012	7.12
2013	6.4
2014	6.31
2015	6.35
2016	6.48
2017	6.67
2018	6.76
2019	8.37
2020	7.11
2021	7.16