On the other hand, Norway, Sweden, and Finland are all above the line, meaning they have higher GDP per capita than predicted. The only nordic country below the line is Denmark, and they are barely below the line.
Oil revenues make such comparisons tricky at best. You would need to consider the hypothetical case of a New Zealand with lots of oil to sell, or a Norway without any.
How exactly Sweden, Finland, Denmark and Iceland benefit anything from oil? It's only Norway that has significant oil reserves, and all other have none.
Well, there's Ikea, Nokia, and... hmm, I'm not sure what economic factors are important in Denmark and Iceland. But I'll bet they're very different than those prevailing in New Zealand, whatever they are.
Oil revenues make such comparisons tricky at best. You would need to consider the hypothetical case of a New Zealand with lots of oil to sell, or a Norway without any.