| 1987 | 2 |
| 1988 | 3 |
| 1989 | 6 |
| 1990 | 12 |
| 1991 | 17 |
| 1992 | 11 |
| 1993 | 22 |
| 1994 | 15 |
| 1995 | 23 |
| 1996 | 29 |
| 1997 | 22 |
| 1998 | 40 |
| 1999 | 21 |
| 2000 | 34 |
| 2001 | 37 |
| 2002 | 34 |
| 2003 | 30 |
| 2004 | 50 |
| 2005 | 209 |
| 2006 | 204 |
| 2007 | 239 |
| 2008 | 230 |
| 2009 | 209 |
| 2010 | 334 |
| 2011 | 389 |
| 2012 | 327 |
| 2013 | 343 |
| 2014 | 437 |
| 2015 | 268 |
| 2016 | 211 |
| 2017 | 144 |
| 2018 | 170 |
| 2019 | 317 |
| 2020 | 274 |
| 2021 | 346 |
| 2022 | 254 |
| 2023 | 134 |
| 2024 | 102 |
| 2025 | 10 |