CREATE TABLE table_name_21 (tonnage INT, date_entered_service VARCHAR)

what is the least tonnage for the ship(s) that entered service on 11 february 1983?
SELECT MIN(tonnage) FROM table_name_21 WHERE date_entered_service = "11 february 1983"
SELECT MIN("tonnage") FROM "table_name_21" WHERE "11 february 1983" = "date_entered_service"