Year	%
1992	40.75
1993	38.27
1994	34.13
1996	21.7
1997	16.59
1998	17.15
1999	16.29
2000	16.23
2001	15.29
2002	12.14
2003	10.68
2004	9.82
2005	9.31
2006	8.9
2007	8.95
2008	8.71
2009	8.1
2010	8.07
2011	8.16
2014	7.78
2015	7.83
2016	7.84
2017	8.35
2018	7.5
2019	5.21
2020	5.13
2021	5.13