| Year | Count |
|---|---|
| 1961 | 5 |
| 1965 | 38 |
| 1966 | 82 |
| 1967 | 129 |
| 1968 | 153 |
| 1969 | 295 |
| 1970 | 424 |
| 1971 | 718 |
| 1972 | 791 |
| 1973 | 696 |
| 1974 | 769 |
| 1975 | 865 |
| 1976 | 820 |
| 1977 | 752 |
| 1978 | 604 |
| 1979 | 675 |
| 1980 | 588 |
| 1981 | 426 |
| 1982 | 433 |
| 1983 | 327 |
| 1984 | 320 |
| 1985 | 283 |
| 1986 | 305 |
| 1987 | 416 |
| 1988 | 354 |
| 1989 | 341 |
| 1990 | 287 |
| 1991 | 252 |
| 1992 | 246 |
| 1993 | 138 |
| 1994 | 117 |
| 1995 | 150 |
| 1996 | 108 |
| 1997 | 109 |
| 1998 | 81 |
| 1999 | 55 |
| 2000 | 26 |
| 2001 | 38 |
| 2002 | 50 |
| 2003 | 72 |
| 2004 | 42 |
| 2005 | 31 |
| 2006 | 20 |
| 2007 | 6 |
| 2008 | 15 |
| 2009 | 21 |
| 2011 | 16 |
| 2013 | 12 |
| 2015 | 5 |
| 2016 | 12 |
| 2018 | 10 |
| 2020 | 15 |
| 2022 | 42 |
| 2023 | 26 |