Year	Number of
1980	25
1981	23
1982	25
1983	24
1984	26
1985	13
1986	13
1987	12
1988	16
1989	18
1990	18
1991	15
1992	16
1993	11
1994	18
1995	12
1996	11
1997	10
1998	17
1999	10
2000	13
2001	12
2002	8
2003	5
2004	11
2005	10
2006	13
2007	12
2008	6
2009	9
2010	22
2011	8
2012	10
2013	11
2014	8
2015	7
2016	6
2017	13
2018	8
2019	13
2020	12