Published data is often not detailed enough for end-users. They wish for «tailor-made» analyses. Principally the NFI-database can be queried according to the needs of any interested party.
This requires the area under investigation to be sufficiently large. For example: The volume should be calculated to be accurate to ±10%, then the forest area should contain about 5'000-15'000 ha. For a similar calculation of the increment you would actually need 10'000-25'000 ha of forest.
To date, the NFI has responded to a multitude of smaller and larger requests (NFI-data analysis 1986-2019, pdf in German). We would be pleased to give you a first consultation free of charge, and we can then make an offer for an analysis according to your needs.
Please use the NFI3-report on results (in German or French), this website (especially the results) and the NFI data catalog (in German) as a first orientation. Go to date of acquisition of NFI-data to find out when the data was collected and the flights took place.