Year	%
1991	10.56
1993	10.15
1996	6.63
1997	6.73
1998	6.54
1999	6.03
2000	5.81
2001	5.64
2002	4.29
2003	4.39
2004	4.36
2005	3.68
2006	4.31
2007	4.39
2008	4.18
2009	4.78
2010	3.63
2011	2.37
2012	2.39
2013	2.44
2014	2.49
2015	2.31
2016	1.41
2017	0.97
2018	0.95
2019	0.83
2020	0.75
2021	0.85