user: Question: What is Fleet Number(s), when Wheel Arrangement is "2-6-0", and when Class is "Z"?
Columns: ['Class', 'Wheel arrangement', 'Fleet number(s)', 'Quantity made', 'Quantity preserved']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['2-6-0 — oOOO — Mogul', '2-6-0 — oOOO — Mogul', '2-6-0 — oOOO — Mogul', '2-6-0 — oOOO — Mogul', '2-6-0 — oOOO — Mogul']
SQL:

assistant: SELECT "Fleet number(s)" FROM "Table" WHERE "Wheel arrangement" = '2-6-0' AND "Class" = 'Z';