Year	Number of
1980	8
1981	3
1982	0
1983	1
1984	3
1985	2
1986	7
1987	0
1988	3
1989	3
1990	1
1991	0
1992	6
1995	0
1996	3
1997	4
1998	4
1999	3
2000	4
2001	1
2002	4
2003	1
2005	6
2006	4
2007	2
2008	1
2009	3
2010	7
2011	6
2012	3
2013	10
2014	3
2016	3
2017	1
2018	5
2019	0
2020	2