Genus: Chroicocephalus
| Year | Arter/grupper | Localities | Participants | Observations |
|---|---|---|---|---|
| 2024 | 1 | 5 | 5 | 5 |
| 2023 | 1 | 4 | 4 | 4 |
| 2022 | 1 | 5 | 5 | 5 |
| 2021 | 1 | 8 | 8 | 8 |
| 2020 | 1 | 8 | 8 | 17 |
| 2019 | 1 | 12 | 12 | 17 |
| 2018 | 1 | 15 | 14 | 23 |
| 2017 | 1 | 9 | 9 | 19 |
| 2016 | 1 | 10 | 10 | 21 |
| 2015 | 1 | 12 | 11 | 19 |
| 2014 | 1 | 12 | 12 | 29 |
| 2013 | 1 | 11 | 11 | 26 |
| 2012 | 1 | 13 | 12 | 31 |
| 2011 | 1 | 10 | 9 | 16 |
| 2010 | 1 | 13 | 12 | 13 |
| 2009 | 1 | 9 | 9 | 11 |
| 2008 | 1 | 17 | 14 | 29 |
| 2007 | 1 | 13 | 8 | 21 |
| 2006 | 1 | 14 | 5 | 26 |
| 2005 | 1 | 9 | 3 | 21 |
| 2004 | 1 | 3 | 3 | 15 |
| 2003 | 1 | 3 | 4 | 27 |
| 2002 | 1 | 5 | 6 | 23 |
| 2001 | 1 | 2 | 2 | 2 |
| 2000 | 1 | 1 | 1 | 1 |
| 1998 | 1 | 1 | 1 | 1 |
| 1994 | 1 | 5 | 5 | 5 |
| 1993 | 1 | 3 | 3 | 3 |
| 1992 | 1 | 2 | 2 | 2 |
| 1989 | 1 | 2 | 2 | 2 |
| Totalt alle år | 1 | 161 | 124 | 442 |
