| Year | Count |
|---|---|
| 1976 | 10 |
| 1977 | 10 |
| 1979 | 18 |
| 1980 | 12 |
| 1981 | 10 |
| 1982 | 13 |
| 1983 | 5 |
| 1984 | 5 |
| 1985 | 5 |
| 1986 | 5 |
| 1988 | 12 |
| 1989 | 7 |
| 1990 | 20 |
| 1991 | 18 |
| 1992 | 27 |
| 1993 | 31 |
| 1994 | 53 |
| 1995 | 33 |
| 1996 | 47 |
| 1997 | 48 |
| 1998 | 80 |
| 1999 | 106 |
| 2000 | 25 |
| 2001 | 43 |
| 2002 | 8 |
| 2003 | 76 |
| 2004 | 55 |
| 2005 | 20 |
| 2006 | 17 |
| 2007 | 12 |
| 2008 | 6 |
| 2009 | 6 |
| 2015 | 15 |
| 2021 | 5 |