| Year | Count |
|---|---|
| 1980 | 5 |
| 1982 | 15 |
| 1983 | 6 |
| 1984 | 5 |
| 1987 | 13 |
| 1988 | 16 |
| 1989 | 6 |
| 1990 | 13 |
| 1991 | 29 |
| 1992 | 17 |
| 1993 | 29 |
| 1994 | 28 |
| 1995 | 70 |
| 1996 | 58 |
| 1997 | 66 |
| 1998 | 110 |
| 1999 | 82 |
| 2000 | 120 |
| 2001 | 136 |
| 2002 | 97 |
| 2003 | 106 |
| 2004 | 166 |
| 2005 | 156 |
| 2006 | 149 |
| 2007 | 152 |
| 2008 | 162 |
| 2009 | 156 |
| 2010 | 183 |
| 2011 | 173 |
| 2012 | 206 |
| 2013 | 247 |
| 2014 | 233 |
| 2015 | 260 |
| 2016 | 383 |
| 2017 | 391 |
| 2018 | 245 |
| 2019 | 312 |
| 2020 | 301 |
| 2021 | 313 |
| 2022 | 317 |
| 2023 | 321 |
| 2024 | 356 |