SELECT class FROM table_name_43 WHERE quantity < 174 AND date = "1921–23"
CREATE TABLE table_name_43 (class VARCHAR, quantity VARCHAR, date VARCHAR)
ชั้นเรียนใดมีปริมาณน้อยกว่า 174 ระหว่างปี 1921–23
Which class has less in quantity than 174 between the years 1921–23?