https://www.infofinland.fi/en/moving-to-finland/non-eu-citizens/remigration-to-finland
”If you have Finnish ancestry or a close connection with Finland, you may be granted a residence permit in Finland on this basis. This means that you are considered a returnee (paluumuuttaja). Receiving a residence permit depends on the directness and closeness of your Finnish ancestry. No other reason, such as work or study, is required in order to receive the permit.”
Not an expert but I would imagine grandparents is considered pretty close and direct.
It makes sense once you consider that these numbers are the manufacturers self reporting. That means they aren’t comparable, so drawing conclusions like ”manufacturer X has better batteries than manufacturer Y” from these numbers is silly.