| Year | Count |
|---|---|
| 1918 | 5 |
| 1933 | 15 |
| 1952 | 5 |
| 1969 | 6 |
| 1970 | 10 |
| 1971 | 48 |
| 1972 | 52 |
| 1973 | 51 |
| 1974 | 112 |
| 1975 | 107 |
| 1976 | 154 |
| 1977 | 136 |
| 1978 | 125 |
| 1979 | 129 |
| 1980 | 82 |
| 1981 | 60 |
| 1982 | 61 |
| 1983 | 10 |
| 1984 | 43 |
| 1985 | 11 |
| 1986 | 12 |
| 1987 | 15 |
| 1988 | 6 |
| 1989 | 15 |
| 1990 | 54 |
| 1991 | 11 |
| 1992 | 39 |
| 1993 | 47 |
| 1994 | 79 |
| 1995 | 53 |
| 1996 | 73 |
| 1997 | 105 |
| 1998 | 103 |
| 1999 | 102 |
| 2000 | 189 |
| 2001 | 179 |
| 2002 | 237 |
| 2003 | 277 |
| 2004 | 255 |
| 2005 | 352 |
| 2006 | 343 |
| 2007 | 268 |
| 2008 | 320 |
| 2009 | 213 |
| 2010 | 144 |
| 2011 | 183 |
| 2012 | 91 |
| 2013 | 86 |
| 2014 | 81 |
| 2015 | 74 |
| 2016 | 31 |
| 2017 | 29 |
| 2018 | 28 |
| 2019 | 17 |
| 2020 | 24 |
| 2022 | 5 |
| 2024 | 6 |