The data for the World Cup winning goalkeepers covers their entire World Cup career rather than just the tournaments in which they were World Cup winners. The ranking is based on the the numbers of goals conceded per 90 minutes played, with Gordon Banks topping the list with 0.43 goals conceded per 90 minutes.
Goalkeepers from the early World Cup, when goals per game were higher have naturally fared less well, despite several of them playing in teams with a 100% record. Turek is one such case, even though he was rested for the infamous 8-3 group defeat to Hungary. Had he played in that, his stats would have looked really ugly!
Surprises for me are that Dino Zoff and Sepp Maier come out relatively far down the list. Maier's numbers were somwhhat spoiled by the 1970 knockout where West Germany prevailed 3-2 against England before losing 4-3 to Italy in the semi-final. And perhaps Italy were not quite as good defensively as their reputation would suggest from 1974 to 1982 when Zoff captained the team on 14 occasions.