| Year | Count |
|---|---|
| 1987 | 20 |
| 1988 | 14 |
| 1989 | 6 |
| 1990 | 19 |
| 1991 | 12 |
| 1992 | 14 |
| 1993 | 9 |
| 1994 | 14 |
| 1995 | 14 |
| 1996 | 9 |
| 1997 | 11 |
| 1998 | 11 |
| 1999 | 15 |
| 2000 | 15 |
| 2001 | 17 |
| 2002 | 21 |
| 2003 | 17 |
| 2004 | 27 |
| 2005 | 23 |
| 2006 | 65 |
| 2007 | 43 |
| 2008 | 41 |
| 2009 | 34 |
| 2010 | 53 |
| 2011 | 38 |
| 2012 | 68 |
| 2013 | 44 |
| 2014 | 69 |
| 2015 | 82 |
| 2016 | 204 |
| 2017 | 276 |
| 2018 | 285 |
| 2019 | 218 |
| 2020 | 284 |
| 2021 | 326 |
| 2022 | 370 |
| 2023 | 388 |
| 2024 | 400 |