Year	Number of
1980	64
1981	3
1982	30
1983	17
1984	14
1985	12
1986	7
1987	3
1988	4
1989	5
1990	5
1991	5
1992	6
1995	3
1996	3
1997	5
1998	7
1999	2
2000	3
2001	6
2002	5
2004	19
2006	5
2007	16
2008	3
2009	2
2010	6
2011	0
2012	4
2013	4
2014	5
2015	0
2016	3
2017	0
2018	1
2019	0
2020	6