| Period | Year | ARIMA | Holt-Winters |
| Bulgaria | |||
| 1 | 2021 | 8.967 | 9.114 |
| 2 | 2022 | 9.461 | 9.275 |
| 3 | 2023 | 9.982 | 9.495 |
| 4 | 2024 | 10.532 | 9.627 |
| Croatia | |||
| 1 | 2021 | 12.215 | 12.394 |
| 2 | 2022 | 12.406 | 12.789 |
| 3 | 2023 | 12.591 | 13.184 |
| 4 | 2024 | 12.770 | 13.578 |
| Greece | |||
| 1 | 2021 | 17.456 | 13.959 |
| 2 | 2022 | 17.523 | 12.394 |
| 3 | 2023 | 17.585 | 10.829 |
| 4 | 2024 | 17.641 | 9.264 |
| Romania | |||
| 1 | 2021 | 12.578 | 11.512 |
| 2 | 2022 | 13.183 | 11.925 |
| 3 | 2023 | 13.808 | 12.338 |
| 4 | 2024 | 14.453 | 12.750 |
| Slovenia | |||
| 1 | 2021 | 22.199 | 22.546 |
| 2 | 2022 | 22.588 | 23.193 |
| 3 | 2023 | 22.969 | 23.840 |
| 4 | 2024 | 23.341 | 24.486 |