| Year | Count |
|---|---|
| 1972 | 5 |
| 1977 | 10 |
| 1981 | 11 |
| 1982 | 7 |
| 1983 | 6 |
| 1984 | 83 |
| 1985 | 46 |
| 1986 | 72 |
| 1987 | 93 |
| 1988 | 47 |
| 1989 | 54 |
| 1990 | 38 |
| 1991 | 43 |
| 1992 | 94 |
| 1993 | 63 |
| 1994 | 45 |
| 1995 | 23 |
| 1996 | 34 |
| 1997 | 25 |
| 1998 | 36 |
| 1999 | 40 |
| 2000 | 26 |
| 2001 | 43 |
| 2002 | 26 |
| 2003 | 42 |
| 2004 | 26 |
| 2005 | 34 |
| 2006 | 26 |
| 2007 | 10 |
| 2008 | 5 |
| 2013 | 5 |