| Year | Count |
|---|---|
| 1974 | 5 |
| 1987 | 5 |
| 1988 | 6 |
| 1990 | 5 |
| 1992 | 12 |
| 1993 | 21 |
| 1994 | 18 |
| 1995 | 20 |
| 1996 | 28 |
| 1997 | 31 |
| 1998 | 63 |
| 1999 | 92 |
| 2000 | 111 |
| 2001 | 76 |
| 2002 | 133 |
| 2003 | 232 |
| 2004 | 200 |
| 2005 | 202 |
| 2006 | 278 |
| 2007 | 259 |
| 2008 | 272 |
| 2009 | 259 |
| 2010 | 229 |
| 2011 | 209 |
| 2012 | 216 |
| 2013 | 250 |
| 2014 | 151 |
| 2015 | 184 |
| 2016 | 169 |
| 2017 | 186 |
| 2018 | 164 |
| 2019 | 160 |
| 2020 | 66 |
| 2021 | 132 |
| 2022 | 80 |
| 2023 | 94 |
| 2024 | 90 |