| Year | Count |
|---|---|
| 1969 | 7 |
| 1970 | 5 |
| 1974 | 8 |
| 1975 | 17 |
| 1976 | 18 |
| 1977 | 28 |
| 1978 | 259 |
| 1979 | 410 |
| 1980 | 335 |
| 1981 | 250 |
| 1982 | 165 |
| 1983 | 192 |
| 1984 | 126 |
| 1985 | 181 |
| 1986 | 115 |
| 1987 | 103 |
| 1988 | 124 |
| 1989 | 98 |
| 1990 | 52 |
| 1991 | 71 |
| 1992 | 52 |
| 1993 | 113 |
| 1993 | 11 |
| 1994 | 75 |
| 1994 | 5 |
| 1995 | 45 |
| 1995 | 5 |
| 1996 | 20 |
| 1997 | 31 |
| 1999 | 31 |
| 2000 | 16 |
| 2002 | 12 |
| 2004 | 10 |