data santoriniInternet and Data. Mobile data tends to be more expensive in Greece. European SIMs will usually have free roaming in Greece. You can get a pre-paid local SIM atAccording to the 2011 census, Santorini had 15,550 permanent residents, and the average age of residents was 37 years (for Greece as a whole it is 44.4 years). 12376 of Santorini’s residents