Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| land formation | area, km² | of which currently forests, km² | % forests | habitat type |
| --- | --- | --- | --- | --- |
| Northern Moldavian Hills | 4630.0 | 476.0 | 10.3% | forest steppe |
| Dniester-Rāut Ridge | 2480.0 | 363.0 | 14.6% | forest steppe |
| Middle Prut Valley | 2930.0 | 312.0 | 10.6% | forest steppe |
| Bălţi Steppe | 1920.0 | 51.0 | 2.7% | steppe |
| Ciuluc-Soloneţ Hills | 1690.0 | 169.0 | 10.0% | forest steppe |
| Corneşti Hills (Codru) | 4740.0 | 1300.0 | 27.5% | forest |
| Lower Dniester Hills | 3040.0 | 371.0 | 12.2% | forest steppe |
| Lower Prut Valley | 1810.0 | 144.0 | 8.0% | forest steppe |
| Tigheci Hills | 3550.0 | 533.0 | 15.0% | forest steppe |
| Bugeac Plain | 3210.0 | 195.0 | 6.1% | steppe |
| part of Podolian Plateau | 1920.0 | 175.0 | 9.1% | forest steppe |
| part of Eurasian Steppe | 1920.0 | 140.0 | 7.3% | steppe |
Question:
When middle prut valley is the land formation what is the highest of which currently forests, km² ?
Answer:
312.0