| Country | 2022 cluster | 2021 cluster | 2020 cluster | 2019 cluster | 2018 cluster |
| Albania | 1 | 1 | 1 | 1 | 1 |
| Bulgaria | 2 | 2 | 2 | 2 | 2 |
| Bosnia and Herzegovina | 2 | 2 | 2 | 2 | 2 |
| Belarus | 3 | 3 | 3 | 3 | 3 |
| The Czech Republic | 1 | 1 | 1 | 1 | 1 |
| Estonia | 1 | 1 | 1 | 1 | 1 |
| Georgia | 2 | 2 | 2 | 2 | 2 |
| Croatia | 2 | 2 | 2 | 2 | 2 |
| Hungary | 3 | 3 | 3 | 3 | 3 |
| Lithuania | 2 | 2 | 2 | 2 | 2 |
| Latvia | 2 | 2 | 2 | 2 | 2 |
| Moldova | 1 | 1 | 1 | 1 | 1 |
| North Macedonia | 3 | 3 | 3 | 3 | 3 |
| Montenegro | 3 | 3 | 3 | 3 | 3 |
| Poland | 1 | 1 | 1 | 1 | 1 |
| Romania | 1 | 1 | 1 | 1 | 1 |
| Russian Federation | 3 | 3 | 3 | 3 | 3 |
| Serbia | 2 | 2 | 2 | 2 | 2 |
| Slovakia | 3 | 3 | 3 | 3 | 3 |
| Slovenia | 3 | 3 | 3 | 3 | 3 |
| Ukraine | 3 | 3 | 3 | 3 | 3 |