Calculate the average number of cast members that appeared in the credit from the 185th to the 193rd episode.
appeared in the credit refers to credited = 'TRUE'; from the 185th to the 193rd episode refers to number_in_series between 185 and 193; cast refers to category = 'Cast'; average number = divide(count(episode_id), 9)
SELECT CAST(COUNT(T1.episode_id) AS REAL) / (193 - 185 + 1) FROM Credit AS T1 INNER JOIN Episode AS T2 ON T1.episode_id = T2.episode_id WHERE T1.category = 'Cast' AND T1.credited = 'true' AND T2.number_in_series BETWEEN 185 AND 193