###HUMAN: Role of narrator, and a Radio Station/Production Company of bbc audiobooks, and a Release/Air Date of 13 november 2008 is what sum of the year?, ###ASSISTANT: SELECT SUM("Year") FROM table_67776 WHERE "Role" = 'narrator' AND "Radio Station/Production Company" = 'bbc audiobooks' AND "Release/Air Date" = '13 november 2008'