I thought the population of NZ and Norway was fairly equal:
| Norway | New Zealand | |
|---|---|---|
| Population: | 5,520,000 | 5,223,0 |
| Source: Country comparison: Norway / New Zealand |
Not much difference in the number of casualties during WWII either:
“New Zealand lost 11928 KIA during WWII”.
Source: https://www.statista.com/statistics/1285448/norwegian-deaths-manpower-wwii/
One of the reasons for the uncertainty is the number of civilians that died in occupied Norway, both from German activities, allied bombing and sabotage activities by Norwegian resistance fighter:
Source: The Norwegian Victims of WW2 - Online Journalism Awards
The exact death toll during the evacuation of Finnmark, due to the German “scourged earth” tactic applied there, and the Russian liberation of part of Finmark in 1944:
Source: Scorching and liberation of Finnmark, a short introduction | Barentsobserver