| Year | Count |
|---|---|
| 1973 | 5 |
| 1976 | 5 |
| 1978 | 11 |
| 1979 | 12 |
| 1980 | 54 |
| 1981 | 54 |
| 1982 | 78 |
| 1983 | 79 |
| 1984 | 47 |
| 1985 | 47 |
| 1986 | 44 |
| 1987 | 65 |
| 1988 | 125 |
| 1989 | 89 |
| 1990 | 101 |
| 1991 | 89 |
| 1992 | 95 |
| 1993 | 75 |
| 1994 | 79 |
| 1995 | 95 |
| 1996 | 68 |
| 1997 | 57 |
| 1998 | 79 |
| 1999 | 37 |
| 2000 | 17 |
| 2001 | 24 |
| 2002 | 48 |
| 2003 | 12 |
| 2004 | 14 |
| 2006 | 14 |
| 2007 | 5 |
| 2008 | 21 |
| 2009 | 5 |
| 2010 | 16 |
| 2011 | 10 |