Year	%
1991	18.56
1993	9.75
1996	6.81
1997	6.82
1998	6.49
1999	6.1
2000	5.83
2001	4.8
2002	3.69
2003	3.74
2004	3.69
2005	3.07
2006	3.38
2007	3.45
2008	3.15
2009	3.67
2010	2.8
2011	1.77
2012	1.81
2013	1.84
2014	1.91
2015	1.9
2016	1.18
2017	0.89
2018	0.86
2019	0.77
2020	0.71
2021	0.81