Year	Percent
1984	2.08
1985	3.82
1986	6.87
1987	5.02
1988	3.71
1989	2.32
1991	2.04
1992	2.77
1993	2.51
1994	2.42
1995	2.98
1996	2.94
1997	2.19
1998	3.01
1999	4.47
2001	3.58
2002	5.44
2003	5.86
2004	5.47
2006	3.78
2007	3.16
2008	3.25
2009	4.75
2010	3.56
2011	3.17
2012	2.9
2013	3.1
2014	3.2
2015	3
2016	3.5