| Year | Count |
|---|---|
| 1943 | 5 |
| 1947 | 5 |
| 1948 | 5 |
| 1949 | 6 |
| 1950 | 6 |
| 1959 | 5 |
| 1960 | 6 |
| 1961 | 6 |
| 1967 | 5 |
| 1968 | 5 |
| 1972 | 6 |
| 1973 | 5 |
| 1978 | 6 |
| 1981 | 16 |
| 1983 | 11 |
| 1984 | 11 |
| 1985 | 36 |
| 1986 | 35 |
| 1987 | 31 |
| 1988 | 58 |
| 1989 | 48 |
| 1990 | 18 |
| 1991 | 41 |
| 1992 | 37 |
| 1993 | 43 |
| 1994 | 39 |
| 1995 | 42 |
| 1996 | 22 |
| 1997 | 19 |
| 1998 | 7 |
| 1999 | 9 |
| 2000 | 20 |
| 2001 | 12 |
| 2002 | 6 |
| 2003 | 5 |
| 2005 | 5 |
| 2006 | 6 |
| 2008 | 5 |