The number ranges granted to fixed telephone networks in different telecommunications areas can be searched for below. If the Operator column says Traficom, it means a number range that has been returned to Traficom but includes numbers ported between the networks of different telecoms operators.
(https://eservices.traficom.fi/LicensesServices/Forms/NureKiinteanPuhelinverkonTilaajanumerot.aspx?langid=en)