| Year | Count |
|---|---|
| 1916 | 5 |
| 1952 | 10 |
| 1954 | 5 |
| 1956 | 7 |
| 1958 | 7 |
| 1961 | 15 |
| 1965 | 8 |
| 1966 | 8 |
| 1967 | 17 |
| 1968 | 32 |
| 1969 | 38 |
| 1970 | 52 |
| 1971 | 74 |
| 1972 | 97 |
| 1973 | 94 |
| 1974 | 144 |
| 1975 | 169 |
| 1976 | 176 |
| 1977 | 214 |
| 1978 | 216 |
| 1979 | 177 |
| 1980 | 258 |
| 1981 | 301 |
| 1982 | 273 |
| 1983 | 284 |
| 1984 | 390 |
| 1985 | 480 |
| 1986 | 430 |
| 1987 | 399 |
| 1988 | 425 |
| 1989 | 349 |
| 1990 | 340 |
| 1991 | 391 |
| 1992 | 344 |
| 1993 | 350 |
| 1994 | 307 |
| 1995 | 225 |
| 1996 | 197 |
| 1997 | 170 |
| 1998 | 145 |
| 1999 | 157 |
| 2000 | 121 |
| 2001 | 89 |
| 2002 | 44 |
| 2003 | 63 |
| 2004 | 68 |
| 2005 | 42 |
| 2006 | 58 |
| 2007 | 15 |
| 2008 | 31 |
| 2009 | 28 |
| 2011 | 9 |