| Year | Count |
|---|---|
| 1983 | 7 |
| 1987 | 6 |
| 1988 | 7 |
| 1989 | 10 |
| 1990 | 12 |
| 1991 | 15 |
| 1992 | 17 |
| 1993 | 21 |
| 1994 | 28 |
| 1995 | 19 |
| 1996 | 22 |
| 1997 | 28 |
| 1998 | 40 |
| 1999 | 43 |
| 2000 | 53 |
| 2001 | 71 |
| 2002 | 76 |
| 2003 | 93 |
| 2004 | 60 |
| 2005 | 78 |
| 2006 | 79 |
| 2007 | 91 |
| 2008 | 85 |
| 2009 | 86 |
| 2010 | 99 |
| 2011 | 99 |
| 2012 | 104 |
| 2013 | 102 |
| 2014 | 107 |
| 2015 | 94 |
| 2016 | 172 |
| 2017 | 228 |
| 2018 | 188 |
| 2019 | 182 |
| 2020 | 87 |
| 2021 | 68 |
| 2022 | 68 |
| 2023 | 72 |
| 2024 | 43 |