Year	Number of
1965	83
1966	78
1967	73
1968	67
1969	62
1970	57
1971	51
1972	46
1973	41
1974	37
1975	34
1976	33
1977	32
1978	31
1979	30
1980	29
1981	28
1982	26
1983	25
1984	24
1985	23
1986	22
1987	22
1988	21
1989	21
1990	21
1991	20
1992	20
1993	19
1994	19
1995	18
1996	17
1997	16
1998	15
1999	14
2000	13
2001	12
2002	12
2003	11
2004	10
2005	10
2006	9
2007	8
2008	8
2009	7
2010	7
2011	7
2012	7
2013	6
2014	7
2015	6