| Year | Count |
|---|---|
| 1989 | 7 |
| 1990 | 14 |
| 1991 | 5 |
| 1992 | 9 |
| 1993 | 34 |
| 1994 | 22 |
| 1995 | 23 |
| 1996 | 69 |
| 1997 | 59 |
| 1998 | 28 |
| 1999 | 45 |
| 2000 | 64 |
| 2001 | 94 |
| 2002 | 53 |
| 2003 | 106 |
| 2004 | 87 |
| 2005 | 78 |
| 2006 | 117 |
| 2007 | 152 |
| 2008 | 243 |
| 2009 | 253 |
| 2010 | 328 |
| 2011 | 316 |
| 2012 | 349 |
| 2013 | 280 |
| 2014 | 323 |
| 2015 | 423 |
| 2016 | 293 |
| 2017 | 313 |
| 2018 | 169 |
| 2019 | 237 |
| 2020 | 156 |
| 2021 | 183 |
| 2022 | 154 |
| 2023 | 104 |
| 2024 | 90 |