| Year | Count |
|---|---|
| 1974 | 8 |
| 1976 | 10 |
| 1977 | 6 |
| 1978 | 8 |
| 1980 | 10 |
| 1982 | 5 |
| 1983 | 6 |
| 1984 | 6 |
| 1985 | 14 |
| 1986 | 101 |
| 1987 | 119 |
| 1988 | 110 |
| 1989 | 108 |
| 1990 | 144 |
| 1991 | 314 |
| 1992 | 206 |
| 1993 | 220 |
| 1994 | 158 |
| 1995 | 142 |
| 1996 | 144 |
| 1997 | 133 |
| 1998 | 102 |
| 1999 | 29 |
| 2000 | 24 |
| 2001 | 56 |
| 2002 | 29 |
| 2003 | 24 |
| 2004 | 14 |
| 2005 | 20 |
| 2006 | 14 |
| 2007 | 12 |
| 2008 | 6 |
| 2010 | 24 |
| 2016 | 7 |