Year	Number of
1980	23
1981	24
1982	5
1983	17
1984	14
1985	14
1987	34
1988	1
1989	30
1991	22
1992	4
1993	11
1994	11
1995	6
1996	8
1997	14
2001	1
2002	19
2003	17
2005	7
2007	2
2009	9
2011	2
2013	2
2014	0
2015	0
2016	0
2018	0
2019	1
2020	0