| Year | Count |
|---|---|
| 1971 | 7 |
| 1973 | 23 |
| 1974 | 12 |
| 1975 | 10 |
| 1976 | 16 |
| 1977 | 53 |
| 1978 | 15 |
| 1979 | 41 |
| 1980 | 13 |
| 1981 | 36 |
| 1982 | 39 |
| 1983 | 58 |
| 1984 | 51 |
| 1985 | 63 |
| 1986 | 44 |
| 1987 | 60 |
| 1988 | 30 |
| 1989 | 32 |
| 1990 | 54 |
| 1991 | 32 |
| 1992 | 65 |
| 1993 | 19 |
| 1994 | 27 |
| 1995 | 41 |
| 1996 | 48 |
| 1997 | 29 |
| 1998 | 46 |
| 1999 | 30 |
| 2000 | 24 |
| 2001 | 29 |
| 2003 | 8 |
| 2007 | 22 |
| 2009 | 5 |
| 2012 | 6 |
| 2022 | 5 |