Does anyone in Greece still believe in the Olympians?

Yes. Now as to the percentage of Christians in this country the 98% is misleading. Consider that we as individuals are not given a choice and are christened in the faith. But that does not mean that we are also believers. I was baptised way back when but I'm an atheist, Practicing christians is another matter. The interesting point here is why there are Dodekatheists. The movement started out as a reaction to the christian faith by a group of people who hold christianity as the main cause and 'killer' of hellenic culture,