| Year | Count |
|---|---|
| 1982 | 6 |
| 1983 | 33 |
| 1984 | 26 |
| 1985 | 396 |
| 1986 | 200 |
| 1987 | 492 |
| 1988 | 239 |
| 1989 | 248 |
| 1990 | 193 |
| 1991 | 221 |
| 1992 | 188 |
| 1993 | 144 |
| 1994 | 130 |
| 1995 | 52 |
| 1996 | 78 |
| 1997 | 59 |
| 1998 | 57 |
| 1999 | 9 |
| 2000 | 44 |
| 2001 | 12 |
| 2002 | 17 |
| 2003 | 32 |
| 2004 | 54 |
| 2005 | 36 |
| 2007 | 31 |
| 2008 | 6 |
| 2010 | 12 |
| 2011 | 10 |
| 2012 | 16 |
| 2013 | 5 |