| Year | Count |
|---|---|
| 1975 | 6 |
| 1976 | 43 |
| 1979 | 30 |
| 1980 | 51 |
| 1981 | 43 |
| 1982 | 62 |
| 1983 | 75 |
| 1984 | 58 |
| 1985 | 84 |
| 1986 | 95 |
| 1987 | 136 |
| 1988 | 139 |
| 1989 | 139 |
| 1990 | 299 |
| 1991 | 338 |
| 1992 | 429 |
| 1993 | 414 |
| 1994 | 496 |
| 1995 | 625 |
| 1996 | 542 |
| 1997 | 563 |
| 1998 | 598 |
| 1999 | 606 |
| 2000 | 549 |
| 2001 | 504 |
| 2002 | 399 |
| 2003 | 423 |
| 2004 | 436 |
| 2005 | 451 |
| 2006 | 455 |
| 2007 | 435 |
| 2008 | 390 |
| 2009 | 325 |
| 2010 | 325 |
| 2011 | 324 |
| 2012 | 219 |
| 2013 | 183 |
| 2014 | 128 |
| 2015 | 181 |
| 2016 | 172 |
| 2017 | 154 |
| 2018 | 92 |
| 2019 | 54 |
| 2020 | 82 |
| 2021 | 60 |
| 2022 | 49 |
| 2023 | 104 |
| 2024 | 100 |