| Year | Count |
|---|---|
| 1969 | 33 |
| 1970 | 40 |
| 1971 | 58 |
| 1972 | 33 |
| 1973 | 44 |
| 1974 | 37 |
| 1975 | 22 |
| 1976 | 37 |
| 1977 | 37 |
| 1978 | 7 |
| 1979 | 36 |
| 1980 | 13 |
| 1981 | 11 |
| 1982 | 5 |
| 1983 | 11 |
| 1985 | 6 |
| 1987 | 23 |
| 1988 | 5 |
| 1989 | 17 |
| 1990 | 26 |
| 1991 | 11 |
| 1992 | 40 |
| 1993 | 14 |
| 1994 | 33 |
| 1995 | 7 |
| 1996 | 7 |
| 1997 | 24 |
| 1998 | 26 |
| 1999 | 7 |
| 2000 | 31 |
| 2001 | 26 |
| 2003 | 6 |
| 2004 | 5 |
| 2007 | 5 |
| 2012 | 6 |