| Year | Count |
|---|---|
| 1978 | 5 |
| 1979 | 6 |
| 1980 | 6 |
| 1982 | 10 |
| 1984 | 5 |
| 1985 | 20 |
| 1986 | 14 |
| 1986 | 10 |
| 1987 | 11 |
| 1987 | 12 |
| 1988 | 29 |
| 1988 | 16 |
| 1989 | 11 |
| 1989 | 40 |
| 1990 | 11 |
| 1990 | 70 |
| 1991 | 63 |
| 1991 | 204 |
| 1992 | 44 |
| 1992 | 227 |
| 1993 | 37 |
| 1993 | 202 |
| 1994 | 63 |
| 1994 | 161 |
| 1995 | 15 |
| 1995 | 126 |
| 1996 | 15 |
| 1996 | 127 |
| 1997 | 6 |
| 1997 | 56 |
| 1998 | 5 |
| 1998 | 51 |
| 1999 | 37 |
| 2000 | 20 |
| 2001 | 12 |
| 2014 | 5 |
| 2020 | 7 |