Table schema:
CREATE TABLE table_name_68 (goals_for INTEGER, wins VARCHAR, goal_difference VARCHAR, club VARCHAR)

Question: What was the average number of "goals for", scored in the club Real Oviedo that had a "goal difference" lower than -16 and fewer than 9 wins?
SQL: SELECT AVG(goals_for) FROM table_name_68 WHERE goal_difference < -16 AND club = "real oviedo" AND wins < 9