When was the film released that a less than 5038 production number and was of the character Bosko?
CREATE TABLE table_name_21 (
    release_date VARCHAR,
    production_num VARCHAR,
    characters VARCHAR
)
SELECT release_date FROM table_name_21 WHERE production_num < 5038 AND characters = "bosko"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: When was the film released that a less than 5038 production number and was of the character Bosko? ### Input: CREATE TABLE table_name_21 (
    release_date VARCHAR,
    production_num VARCHAR,
    characters VARCHAR
) ### Response: SELECT release_date FROM table_name_21 WHERE production_num < 5038 AND characters = "bosko"