Year	Percent
1976	0.48
1978	0.29
1979	0.44
1980	0.56
1982	1.97
1984	3.14
1987	4.12
1988	2.1
1989	0.93
1990	1.35
1994	1.24
1996	0.94
1997	0.82
1998	3.28
1999	2.69
2000	2.23
2001	1.61
2003	0.9
2004	1
2005	0.8
2006	0.69
2007	0.68
2008	0.67
2009	0.98
2010	0.41
2011	0.39
2012	0.33
2013	0.15
2014	0.32
2015	0.37
2016	0.41
2017	0.53
2018	0.49
2019	0.42
2020	0.82