Year	Percent
1983	6.83
1984	5.69
1985	6.52
1986	3.62
1987	4.13
1988	3.66
1989	3.71
1990	3.51
1991	2.63
1992	2.04
1993	2.33
1994	2.12
1995	1.88
1996	1.48
1997	1.84
1998	2
1999	1.8
2000	1.9
2001	1.48
2002	1.16
2003	1.35
2004	0.92
2005	0.9
2006	0.87
2007	0.98
2008	0.87
2009	1.02
2010	0.92
2011	0.77
2012	0.89
2013	1
2014	0.81
2015	0.93
2016	0.89
2017	0.62