Year	%
1991	13.03
1995	7.5
1996	12.16
1997	12.48
1998	12.22
1999	5.89
2000	14.64
2001	14.51
2002	4.8
2003	14.51
2004	3.17
2005	3.15
2006	2.51
2007	2.53
2008	2.11
2009	1.72
2010	4.22
2011	4.1
2012	3.76
2013	3.69
2014	1.1
2015	3.75
2016	3.85
2017	1.37
2018	1.37