| Year | Count |
|---|---|
| 1968 | 5 |
| 1975 | 14 |
| 1976 | 25 |
| 1977 | 56 |
| 1978 | 55 |
| 1979 | 53 |
| 1980 | 77 |
| 1981 | 46 |
| 1982 | 38 |
| 1983 | 41 |
| 1984 | 43 |
| 1985 | 48 |
| 1986 | 36 |
| 1987 | 49 |
| 1988 | 55 |
| 1989 | 54 |
| 1990 | 59 |
| 1991 | 23 |
| 1992 | 65 |
| 1993 | 65 |
| 1994 | 16 |
| 1995 | 53 |
| 1996 | 31 |
| 1997 | 47 |
| 1998 | 51 |
| 1999 | 5 |
| 2000 | 18 |
| 2001 | 5 |
| 2002 | 15 |
| 2003 | 21 |
| 2004 | 69 |
| 2005 | 49 |
| 2006 | 10 |
| 2007 | 29 |
| 2008 | 16 |
| 2009 | 12 |
| 2010 | 11 |
| 2012 | 12 |
| 2019 | 7 |
| 2020 | 6 |
| 2022 | 19 |