user: Question: How many trains depart at 17:30?
Columns: ['Train No.', 'Train Name', 'Arrival', 'Departure', 'Days', 'Platform No.']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [5037.0, 'Kanpur - Farrukhabad Express', '10:55', '11:05', 'Daily', 'Platform No.2']
SQL:

assistant: SELECT COUNT("Train No.") FROM "Table" WHERE "Departure" = '17:30';