CREATE TABLE table_name_87 (fleet_size INT, type VARCHAR, introduced VARCHAR)

What is the smallest fleet size with a type of shunter introduced in 1953?
SELECT MIN(fleet_size) FROM table_name_87 WHERE type = "shunter" AND introduced = "1953"
SELECT MIN("fleet_size") FROM "table_name_87" WHERE "1953" = "introduced" AND "shunter" = "type"