Also worth mentioning for the period prior to 1950:

• Agriculture consisted of more manual labour, as tractors were not widespread at all.
  
• Good soil for farming is sparse in most parts of the country, except for the inner parts of Østlandet. Even if you could break land, the soil still used to be quite inferior compared to pretty much anywhere else in Europe.
  
• That's not really helped by the lack of sunlight, which is rather important for growing just about anything. Up north summers are short, out west summers are notoriously wet. Which is why most people farming for sustenance, still had to be fishers as well.
  
• Fishing, and especially when it's done for the sake of staying alive rather than out of leisure ever so often on the weekends, can be quite dangerous. There are a thousand ways to kill yourself during winter, in a small boat in shitty weather in Norway.
  
• Out in the rural areas, you did have access to a doctor, in the nearest town, quite a distance away.

Infant mortality was high. As was mortality after infancy. My late grandmother had three siblings who survived to old age. She started out with eight. But you were almost half-expected to loose a good few along the way. One died from illness, one was lost at sea during fishing, one died while logging, and two went to sea as part of the merchant marine during the war, and didn't come back. And her generation was at the watershed when a whole lot of western civilization caught up with parts of Norway, leading to industrialization, leaps in medicine and so on.

I know jack shit about my great grandfather's generation. The church-books for the area where he lived were burnt by the Germans, so anything not remembered and written down after 1945 is lost to the ages.

So it's really no wonder people decided to GTFO.