| Year | Count |
|---|---|
| 1974 | 27 |
| 1975 | 16 |
| 1976 | 39 |
| 1977 | 55 |
| 1978 | 29 |
| 1979 | 91 |
| 1980 | 97 |
| 1981 | 105 |
| 1982 | 114 |
| 1983 | 87 |
| 1984 | 102 |
| 1985 | 129 |
| 1986 | 118 |
| 1987 | 163 |
| 1988 | 179 |
| 1989 | 204 |
| 1990 | 212 |
| 1991 | 285 |
| 1992 | 373 |
| 1993 | 315 |
| 1994 | 291 |
| 1995 | 344 |
| 1996 | 377 |
| 1997 | 341 |
| 1998 | 444 |
| 1999 | 440 |
| 2000 | 583 |
| 2001 | 501 |
| 2002 | 386 |
| 2003 | 390 |
| 2004 | 372 |
| 2005 | 377 |
| 2006 | 452 |
| 2007 | 396 |
| 2008 | 400 |
| 2009 | 401 |
| 2010 | 385 |
| 2011 | 351 |
| 2012 | 482 |
| 2013 | 442 |
| 2014 | 471 |
| 2015 | 577 |
| 2016 | 520 |
| 2017 | 589 |
| 2018 | 513 |
| 2019 | 539 |
| 2020 | 335 |
| 2021 | 434 |
| 2022 | 503 |
| 2023 | 484 |
| 2024 | 449 |