Not that surprising. Up until fairly recently, they were a homogenous nation with no parasitic underclass (read schvartzes or Muzzies), high per capita income and a socialist system that actually shared the wealth pretty well (not that it could ever work in America), a very moderate birthrate (no widespread domestic drudgery), and they have mild weather to boot (compared to California at least!)
I expect all of the above to change quickly though, as the nation, like the rest of Scandiniavia, is completely overrun by Islamic beasts.