This would appear to be based on the IoM postcodes (not directly linked to parish boundaries - from the boundaries would appear to be the major region (eg IM1 douglas + the first digit of 2nd part) and the entries in the Manx telephone directory - a similar version was mentioned here some time ago - at that time the version conflated business names and personal entries thus heavily overemphazing some names - the major problem is the small number of entries in most areas thus one or two over represented names areak havoc - the towns which have enough entries to make the statistics sensible have so much mixing of names as to render it almost useless