Year	%
1991	11.87
1993	6.18
1994	9.21
1995	5.39
1996	6.61
1997	7.64
1998	3.63
1999	5.78
2000	3.86
2001	6.48
2002	5.92
2003	2.84
2004	3.22
2005	5.42
2006	2.38
2007	4.85
2008	5.06
2009	4.69
2010	3.67
2011	4.35
2012	5.09
2013	4.35
2014	4.45
2015	2.94
2016	2.9
2017	3.13