user: ### NOW ANSWER:
Question: Which year has a fleet number of 603?
Columns: ['Year', 'Model', 'Length', 'Width', 'Fleet Number']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1970', 'GMC T6H4521A', "35'", '96"', '101-103']
SQL:

assistant: SELECT "Year" FROM "Table" WHERE "Fleet Number" = '603';