| Year | Count |
|---|---|
| 1971 | 7 |
| 1972 | 9 |
| 1976 | 5 |
| 1977 | 24 |
| 1978 | 6 |
| 1979 | 19 |
| 1983 | 6 |
| 1985 | 5 |
| 1986 | 12 |
| 1987 | 7 |
| 1988 | 9 |
| 1989 | 15 |
| 1990 | 6 |
| 1995 | 21 |
| 1996 | 11 |
| 1997 | 18 |
| 1999 | 24 |
| 2000 | 45 |
| 2001 | 81 |
| 2002 | 59 |
| 2003 | 79 |
| 2004 | 202 |
| 2005 | 230 |
| 2006 | 212 |
| 2007 | 352 |
| 2008 | 328 |
| 2009 | 256 |
| 2010 | 256 |
| 2011 | 302 |
| 2012 | 333 |
| 2013 | 381 |
| 2014 | 302 |
| 2015 | 318 |
| 2016 | 392 |
| 2017 | 509 |
| 2018 | 388 |
| 2019 | 343 |
| 2020 | 415 |
| 2021 | 407 |
| 2022 | 508 |
| 2023 | 544 |
| 2024 | 561 |