4. Materials and services
| EUR 1,000 | 2020 | 2019 |
| Purchases during the period | -1,618 | -641 |
| Increase/decrease in inventories | 303 | |
| Materials and supplies | -1,618 | -338 |
| External services | -1,129 | -1,710 |
| Materials and services total | -2,747 | -2,048 |
| EUR 1,000 | 2020 | 2019 |
| Purchases during the period | -1,618 | -641 |
| Increase/decrease in inventories | 303 | |
| Materials and supplies | -1,618 | -338 |
| External services | -1,129 | -1,710 |
| Materials and services total | -2,747 | -2,048 |