| Year | Count |
|---|---|
| 1931 | 5 |
| 1939 | 6 |
| 1940 | 10 |
| 1949 | 12 |
| 1952 | 15 |
| 1953 | 15 |
| 1954 | 5 |
| 1955 | 12 |
| 1956 | 10 |
| 1958 | 17 |
| 1967 | 14 |
| 1969 | 5 |
| 1980 | 7 |
| 1984 | 5 |
| 1985 | 12 |
| 1986 | 5 |
| 1987 | 28 |
| 1988 | 6 |
| 1989 | 5 |
| 1990 | 14 |
| 1991 | 19 |
| 1992 | 16 |
| 1993 | 31 |
| 1994 | 12 |
| 1995 | 10 |
| 1996 | 8 |
| 1997 | 16 |
| 1998 | 5 |
| 1999 | 14 |
| 2000 | 16 |
| 2001 | 9 |
| 2002 | 10 |
| 2003 | 20 |
| 2004 | 19 |
| 2005 | 10 |
| 2010 | 6 |
| 2013 | 6 |