Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_15 (goals_against INTEGER, club VARCHAR, points VARCHAR)
### Question:
Which Goals against have a Club of cd castellón, and Points smaller than 24?
### Answer:
SELECT AVG(goals_against) FROM table_name_15 WHERE club = "cd castellón" AND points < 24