| Year | Count |
|---|---|
| 1974 | 6 |
| 1975 | 5 |
| 1976 | 18 |
| 1977 | 16 |
| 1978 | 23 |
| 1979 | 80 |
| 1980 | 46 |
| 1981 | 42 |
| 1982 | 72 |
| 1983 | 67 |
| 1984 | 60 |
| 1985 | 112 |
| 1986 | 175 |
| 1987 | 340 |
| 1988 | 417 |
| 1989 | 429 |
| 1990 | 368 |
| 1991 | 406 |
| 1992 | 501 |
| 1993 | 464 |
| 1994 | 390 |
| 1995 | 307 |
| 1996 | 227 |
| 1997 | 284 |
| 1998 | 339 |
| 1999 | 347 |
| 2000 | 333 |
| 2001 | 593 |
| 2002 | 337 |
| 2003 | 369 |
| 2004 | 331 |
| 2005 | 306 |
| 2006 | 261 |
| 2007 | 354 |
| 2008 | 317 |
| 2009 | 193 |
| 2010 | 248 |
| 2011 | 184 |
| 2012 | 146 |
| 2013 | 127 |
| 2014 | 95 |
| 2015 | 68 |
| 2016 | 59 |
| 2017 | 39 |
| 2018 | 16 |
| 2019 | 18 |
| 2020 | 23 |
| 2021 | 28 |
| 2022 | 67 |
| 2023 | 30 |
| 2024 | 5 |