user: Question: What is Date, when Type is DS4-4-750, and when Works Number is 74409?
Columns: ['Number', 'Builder', 'Type', 'Date', 'Works number']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['51', 'Baldwin Locomotive Works', 'DS4-4-750', '1949', '74408']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Type" = 'DS4-4-750' AND "Works number" = '74409';