Year	Percent
1982	2.97
1983	3.36
1984	2.05
1985	2.85
1986	2.33
1987	3.83
1988	4.7
1989	3.35
1992	2.17
1993	2.43
1994	1.59
1995	2.98
1996	2.83
1997	2.85
1998	2.85
1999	2.08
2000	1.79
2001	3.28
2002	3.2
2003	3.97
2004	3.62
2005	5.51
2006	5.03
2007	3.98
2008	4.45
2009	7.43
2010	6.8
2011	5.37
2012	7.17
2013	7.75
2014	6.5
2015	6.07
2016	7.24
2017	6.57