Year	Number of
1980	0
1981	2
1982	8
1983	0
1984	0
1985	0
1986	8
1987	6
1988	8
1989	0
1990	7
1994	4
1999	2
2000	4
2001	3
2002	5
2003	3
2005	11
2006	12
2007	3
2008	5
2009	4
2010	3
2011	5
2014	8
2015	10
2016	10
2017	9
2018	5
2019	17
2020	13