Year	Percent
1985	2.13
1987	5.99
1988	4.92
1989	5.06
1990	4.9
1991	4.94
1992	3.71
1993	5.42
1994	5.33
1995	4.66
1996	3.93
1997	4.56
1998	4.9
1999	3.5
2000	4.27
2001	0.2509
2002	4.54
2003	0.2883
2004	0.3072
2005	0.3929
2006	0.3057
2007	0.2892
2008	0.2041
2009	0.2056
2010	0.2954
2011	0.2446
2012	0.2866
2013	0.3271
2014	0.254
2016	0.3704
2017	0.3292