Plusia
Observations/month
| Month | 1992–2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | total | |
|---|
| Januar | | | | | | | | | | | | | | | | | |
| Februar | | | | | | | | | | | | | | | | | |
| Mars | | | | | | | | | | | | | | | | | |
| April | | | | | | | | | | | | | | | | | |
| Mai | 1 | | | | | | | | | | | | | | | 0 % | |
| Juni | 2 | | | | | | | 1 | | 2 | | | | | | 2 % | |
| Juli | 11 | 15 | 19 | 15 | 17 | 13 | 1 | 7 | 10 | 7 | 6 | 1 | 1 | 4 | 1 | 62 % | |
| August | 17 | 4 | 4 | 4 | 1 | 2 | 24 | | 2 | 1 | 1 | | 1 | 1 | 1 | 30 % | |
| September | 3 | | | | | 7 | | | | | | | | | | 5 % | |
| Oktober | | | | | | | | | | | | | | | | | |
| November | | | | | | | | | | | | | | | | | |
| Desember | | | | | | | | | | | | | | | | | |