user: Question: What year is the date when the boiler type is forward topfeed, the built at is crewe, and lot number is less than 187?
Columns: ['BR No.', 'Lot No.', 'Date', 'Built at', 'Boiler type']
Types: ['text', 'real', 'real', 'text', 'text']
Sample row: ['44658–67', 199.0, 1949.0, 'Crewe', 'Forward topfeed']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Boiler type" = 'forward topfeed' AND "Built at" = 'crewe' AND "Lot No." < 187.0;