| Year | Count |
|---|---|
| 1978 | 10 |
| 1987 | 5 |
| 1988 | 10 |
| 1991 | 10 |
| 1992 | 25 |
| 1994 | 5 |
| 1995 | 16 |
| 1996 | 24 |
| 1997 | 30 |
| 1998 | 51 |
| 1999 | 42 |
| 2000 | 40 |
| 2001 | 73 |
| 2002 | 100 |
| 2003 | 76 |
| 2004 | 202 |
| 2005 | 207 |
| 2006 | 251 |
| 2007 | 323 |
| 2008 | 457 |
| 2009 | 402 |
| 2010 | 497 |
| 2011 | 638 |
| 2012 | 784 |
| 2013 | 631 |
| 2014 | 554 |
| 2015 | 926 |
| 2016 | 1,007 |
| 2017 | 1,127 |
| 2018 | 1,017 |
| 2019 | 1,152 |
| 2020 | 1,231 |
| 2021 | 1,328 |
| 2022 | 1,374 |
| 2023 | 1,142 |
| 2024 | 990 |