| Year | Count |
|---|---|
| 1959 | 5 |
| 1962 | 10 |
| 1965 | 16 |
| 1966 | 18 |
| 1967 | 18 |
| 1969 | 7 |
| 1971 | 8 |
| 1972 | 5 |
| 1973 | 6 |
| 1976 | 5 |
| 1977 | 5 |
| 1978 | 5 |
| 1981 | 5 |
| 1982 | 5 |
| 1984 | 6 |
| 1985 | 24 |
| 1986 | 16 |
| 1987 | 11 |
| 1988 | 7 |
| 1989 | 38 |
| 1990 | 60 |
| 1991 | 108 |
| 1992 | 112 |
| 1993 | 98 |
| 1994 | 111 |
| 1995 | 109 |
| 1996 | 202 |
| 1997 | 456 |
| 1998 | 614 |
| 1999 | 414 |
| 2000 | 452 |
| 2001 | 400 |
| 2002 | 456 |
| 2003 | 592 |
| 2004 | 590 |
| 2005 | 592 |
| 2006 | 578 |
| 2007 | 436 |
| 2008 | 630 |
| 2009 | 619 |
| 2010 | 565 |
| 2011 | 474 |
| 2012 | 465 |
| 2013 | 453 |
| 2014 | 348 |
| 2015 | 347 |
| 2016 | 365 |
| 2017 | 263 |
| 2018 | 363 |
| 2019 | 308 |
| 2020 | 317 |
| 2021 | 415 |
| 2022 | 425 |
| 2023 | 414 |
| 2024 | 396 |