I never mind seeing gross summary statistics like this. But in terms of drawing any conclusions, I think you'd need to address two big area.

You don't factor in cost of living in these different countries. That varies enormously, and could seriously affect your happiness there. Heck, it varies hugely within country too. $100,000 is not so much in the US's Bay Area as it is in rural Maine.

It's hard to believe there aren't significant interactions between your variables. Maybe education level doesn't matter much for some positions, or in some countries for instance, but a lot in others.