Hello. w:el:Πρότυπο:Διοικητική Διαίρεση (Κύπρος). The template is using data from wikidata about population. The problem above is not about wikidata, is about the template and how it works.
If a census is missing, then the %± is not showing anything in the next census. Like, w:el:Γενί Τζαμί (συνοικία Λευκωσίας). Is not showing anything between 1921 and 1946 becauce 1931 is missing.
But, in w:el:Κούρδαλι, the %± is showing between 1931 and 1976, even thought there are some census betwwen them. Why that happen?