| Year | Count |
|---|---|
| 1917 | 6 |
| 1969 | 5 |
| 1975 | 9 |
| 1976 | 6 |
| 1977 | 6 |
| 1979 | 9 |
| 1982 | 5 |
| 1983 | 9 |
| 1984 | 8 |
| 1985 | 12 |
| 1986 | 19 |
| 1987 | 27 |
| 1988 | 18 |
| 1989 | 19 |
| 1990 | 25 |
| 1991 | 31 |
| 1992 | 27 |
| 1993 | 28 |
| 1994 | 23 |
| 1995 | 32 |
| 1996 | 33 |
| 1997 | 29 |
| 1998 | 47 |
| 1999 | 54 |
| 2000 | 45 |
| 2001 | 53 |
| 2002 | 52 |
| 2003 | 55 |
| 2004 | 47 |
| 2005 | 47 |
| 2006 | 61 |
| 2007 | 47 |
| 2008 | 67 |
| 2009 | 77 |
| 2010 | 68 |
| 2011 | 58 |
| 2012 | 66 |
| 2013 | 77 |
| 2014 | 67 |
| 2015 | 61 |
| 2016 | 136 |
| 2017 | 130 |
| 2018 | 102 |
| 2019 | 96 |
| 2020 | 64 |
| 2021 | 54 |
| 2022 | 38 |
| 2023 | 27 |
| 2024 | 34 |