CREATE TABLE table_name_61 (size VARCHAR(255), school VARCHAR(255), _number___county VARCHAR(255), year_joined VARCHAR(255), ihsaa_class VARCHAR(255))
What's the size of Centerville in 89 Wayne county with an IHSAA class of AA in the year before 1974?
    
SQL: SELECT size FROM table_name_61 WHERE year_joined < 1974 AND ihsaa_class = "aa" AND _number___county = "89 wayne" AND school = "centerville"