| Year | Count |
|---|---|
| 1957 | 10 |
| 1958 | 10 |
| 1959 | 24 |
| 1960 | 14 |
| 1961 | 28 |
| 1963 | 5 |
| 1964 | 6 |
| 1965 | 6 |
| 1966 | 9 |
| 1967 | 6 |
| 1968 | 9 |
| 1969 | 8 |
| 1970 | 7 |
| 1972 | 8 |
| 1974 | 7 |
| 1976 | 10 |
| 1977 | 24 |
| 1978 | 32 |
| 1979 | 10 |
| 1981 | 11 |
| 1982 | 8 |
| 1984 | 9 |
| 1985 | 9 |
| 1986 | 7 |
| 1988 | 7 |
| 1989 | 5 |
| 1993 | 7 |
| 1994 | 5 |
| 1995 | 8 |
| 1997 | 7 |
| 1998 | 5 |
| 1999 | 7 |
| 2000 | 7 |
| 2001 | 7 |
| 2002 | 6 |
| 2003 | 7 |
| 2005 | 6 |
| 2011 | 5 |
| 2012 | 5 |
| 2014 | 6 |
| 2015 | 18 |
| 2023 | 10 |