| Year | Count |
|---|---|
| 1979 | 10 |
| 1981 | 24 |
| 1982 | 67 |
| 1983 | 38 |
| 1984 | 82 |
| 1985 | 68 |
| 1986 | 81 |
| 1987 | 157 |
| 1988 | 148 |
| 1989 | 107 |
| 1990 | 144 |
| 1991 | 352 |
| 1992 | 386 |
| 1993 | 358 |
| 1994 | 445 |
| 1995 | 387 |
| 1996 | 402 |
| 1997 | 470 |
| 1998 | 429 |
| 1999 | 371 |
| 2000 | 412 |
| 2001 | 432 |
| 2002 | 355 |
| 2003 | 303 |
| 2004 | 512 |
| 2005 | 510 |
| 2006 | 363 |
| 2007 | 321 |
| 2008 | 306 |
| 2009 | 244 |
| 2010 | 287 |
| 2011 | 208 |
| 2012 | 173 |
| 2013 | 130 |
| 2014 | 119 |
| 2015 | 126 |
| 2016 | 94 |
| 2017 | 66 |
| 2018 | 69 |
| 2019 | 22 |
| 2020 | 59 |
| 2021 | 30 |
| 2022 | 47 |
| 2023 | 51 |
| 2024 | 11 |