Year	Percent
1983	3.03
1984	2.57
1985	2.47
1986	2.18
1987	2.29
1988	2.09
1989	1.87
1990	1.9
1991	1.8
1992	1.9
1993	1.78
1994	1.43
1995	1.17
1996	0.98
1997	1.13
1998	1.26
1999	1.02
2000	0.94
2001	0.86
2002	0.83
2003	0.72
2004	0.86
2005	0.79
2006	0.69
2007	0.59
2008	0.41
2009	0.39
2010	0.29
2011	0.26
2012	0.26
2013	0.17
2014	0.21
2015	0.3
2016	0.78
2017	0.4