| Year | Count |
|---|---|
| 1987 | 6 |
| 1991 | 5 |
| 1992 | 13 |
| 1993 | 6 |
| 1996 | 11 |
| 1997 | 7 |
| 1998 | 25 |
| 1999 | 45 |
| 2000 | 39 |
| 2001 | 32 |
| 2002 | 27 |
| 2003 | 17 |
| 2004 | 14 |
| 2005 | 19 |
| 2006 | 23 |
| 2007 | 21 |
| 2008 | 22 |
| 2009 | 27 |
| 2010 | 16 |
| 2011 | 25 |
| 2012 | 18 |
| 2013 | 21 |
| 2014 | 28 |
| 2015 | 31 |
| 2016 | 135 |
| 2017 | 90 |
| 2018 | 29 |
| 2019 | 88 |
| 2020 | 64 |
| 2021 | 48 |
| 2022 | 36 |
| 2023 | 68 |
| 2024 | 42 |