Table schema:
CREATE TABLE table_name_81 (goals_for INTEGER, goal_difference VARCHAR, points VARCHAR, goals_against VARCHAR)

Question: What is the average number of goals with more than 9 points, less than 14 goals against, and a goal difference less than 17?
SQL: SELECT AVG(goals_for) FROM table_name_81 WHERE points > 9 AND goals_against < 14 AND goal_difference < 17