Year	Percent
1982	4.38
1983	3.86
1984	3.38
1987	4.5
1988	5.3
1989	7
1990	7.13
1991	5.33
1992	6.14
1993	8.5
1994	10.34
1995	16.5
1996	15.73
1997	12.91
1998	11.71
1999	13.28
2000	14.05
2001	17.41
2002	20.13
2003	13.73
2004	11.8342
2005	9.9977
2006	8.3622
2008	6.4747
2009	7.757
2010	6.6474
2011	6.2403
2012	6.0644
2013	6.1049
2014	6.4686
2017	7.513