| Year | Count |
|---|---|
| 1974 | 12 |
| 1975 | 46 |
| 1976 | 75 |
| 1977 | 211 |
| 1978 | 336 |
| 1979 | 395 |
| 1980 | 323 |
| 1981 | 261 |
| 1982 | 218 |
| 1983 | 138 |
| 1984 | 119 |
| 1985 | 91 |
| 1986 | 37 |
| 1987 | 40 |
| 1988 | 50 |
| 1989 | 57 |
| 1990 | 24 |
| 1991 | 51 |
| 1992 | 30 |
| 1993 | 54 |
| 1994 | 118 |
| 1995 | 34 |
| 1996 | 53 |
| 1997 | 44 |
| 1998 | 33 |
| 1999 | 8 |
| 2000 | 27 |
| 2001 | 16 |
| 2002 | 10 |
| 2003 | 14 |
| 2004 | 18 |
| 2007 | 6 |