| Year | Count |
|---|---|
| 1988 | 8 |
| 1989 | 38 |
| 1990 | 35 |
| 1991 | 35 |
| 1992 | 38 |
| 1993 | 34 |
| 1994 | 39 |
| 1995 | 48 |
| 1996 | 47 |
| 1997 | 48 |
| 1998 | 44 |
| 1999 | 46 |
| 2000 | 42 |
| 2001 | 44 |
| 2002 | 34 |
| 2003 | 39 |
| 2004 | 35 |
| 2005 | 43 |
| 2006 | 44 |
| 2007 | 47 |
| 2008 | 92 |
| 2009 | 90 |
| 2010 | 111 |
| 2011 | 152 |
| 2012 | 176 |
| 2013 | 238 |
| 2014 | 180 |
| 2015 | 215 |
| 2016 | 420 |
| 2017 | 414 |
| 2018 | 472 |
| 2019 | 516 |
| 2020 | 215 |
| 2021 | 216 |
| 2022 | 179 |
| 2023 | 175 |
| 2024 | 146 |