The annual hypothetical tax base amounts to NOK 17 billion in 2015–2019 and NOK 50 billion in 2020–2023, based on tax assessment values and expressed in 2025 prices. Corresponding estimates based on estimated market values are NOK 27 and 90 billion, respectively. A small number of donors account for a large share of the tax base, and only a modest portion (15 percent) is related to inheritances.