Which fleet numbers has quantity of 1?
CREATE TABLE table_49531 (
    "Class" text,
    "Wheel arrangement" text,
    "Fleet number(s)" text,
    "Manufacturer" text,
    "Year made" text,
    "Quantity made" text,
    "Quantity preserved" text
)
SELECT "Fleet number(s)" FROM table_49531 WHERE "Quantity made" = '1'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Which fleet numbers has quantity of 1? ### Input: CREATE TABLE table_49531 (
    "Class" text,
    "Wheel arrangement" text,
    "Fleet number(s)" text,
    "Manufacturer" text,
    "Year made" text,
    "Quantity made" text,
    "Quantity preserved" text
) ### Response: SELECT "Fleet number(s)" FROM table_49531 WHERE "Quantity made" = '1'