There has been much talk about how Finland plummeted from its traditional top spot in the PISA scores, but:
Overall, though, across all three subjects, Finland was still #1 in Europe and its diaspora.
In contrast, the Scandinavian countries did not excel in 2012, with overall means of 498 for Denmark, 496 for oil-rich Norway, and 482 for Sweden. Among members of the OECD, the rich countries' club, Sweden beat only Israel, Slovakia, Greece, Turkey, Chile, and Mexico. (Some of those countries that Sweden edged out are in the rich countries' club only for "courtesy" or "aspirational" reasons.)