Year	Percent
1992	0.84
1993	0.7
1994	0.63
1995	0.38
1996	0.38
1997	0.75
1998	0.44
1999	0.98
2000	0.6
2001	4.79
2002	3.41
2003	4.61
2004	3.5
2005	3.37
2006	2.12
2007	3.22
2008	2.73
2009	3.63
2010	2.98
2011	2.81
2012	2.82
2013	2.64
2014	2.53
2015	2.34
2016	2.2
2017	2.02