| Year | Count |
|---|---|
| 1961 | 6 |
| 1970 | 10 |
| 1974 | 5 |
| 1975 | 6 |
| 1976 | 23 |
| 1977 | 27 |
| 1978 | 12 |
| 1979 | 34 |
| 1980 | 11 |
| 1981 | 7 |
| 1982 | 23 |
| 1983 | 20 |
| 1984 | 10 |
| 1985 | 51 |
| 1986 | 38 |
| 1987 | 32 |
| 1988 | 16 |
| 1989 | 15 |
| 1990 | 39 |
| 1991 | 65 |
| 1992 | 9 |
| 1995 | 11 |
| 1996 | 14 |
| 1997 | 5 |
| 1998 | 24 |
| 1999 | 6 |
| 2001 | 5 |
| 2003 | 14 |
| 2004 | 25 |
| 2005 | 23 |
| 2006 | 5 |
| 2007 | 22 |
| 2008 | 19 |
| 2010 | 5 |
| 2011 | 5 |
| 2014 | 5 |
| 2015 | 6 |
| 2016 | 6 |
| 2022 | 5 |