SELECT date FROM table_name_89 WHERE winning_score = −9(72 - 68 - 64 - 67 = 271)
CREATE TABLE table_name_89 (date VARCHAR, winning_score VARCHAR)
คะแนนชนะคือเมื่อใด −9 (72-68-64-67=271)?
When was the winning score −9 (72-68-64-67=271)?