user: ### NOW ANSWER:
Question: Which Built has a Builder of BREL Crewe?
Columns: ['Railway', 'Builder', 'Built', 'Wheels', 'Location', 'ObjectNumber']
Types: ['text', 'text', 'real', 'text', 'text', 'text']
Sample row: ['C&SLR', 'Mather & Platt / Beyer, Peacock', 1890.0, 'Bo', 'LTMuseum', '1923-301']
SQL:

assistant: SELECT AVG("Built") FROM "Table" WHERE "Builder" = 'BREL Crewe';