So yes I was comparing per-capita. However Norway is so tiny that fluctuations of even +/- 50% year-to-year are likely to be just noise.
A tiny country may have one homicide one year, then three the next. Or as a journalist would put it: "Murders in Norway skyrocket. Up 200%."
I don't think it's a fair comparison just because absolute population is similar.
If Norway had the same homicide rate as the whole of the US in 2019 (as it doesn't seem they've release the 2020 ones yet), according to the FBI[1] the homicide rate in the US was 5.0 murders per 100,000 people. Norway has a population of 5.4 million.
So for Norway, that would have been 270.
Does that seem like a fluctuation?
You're severely misrepresenting the facts as your figures are out by two orders of magnitude.
[1]https://ucr.fbi.gov/crime-in-the-u.s/2019/crime-in-the-u.s.-....
That's an order of magnitude off from the homicide rate of the US, which you just quoted.
Why are you even using the US' homicide rate and applying it to Norway?
because they are considered simarly developed countries, but as far as violence stats go (especially gun violence) USA is more comparable to developing countries.