user: ### NOW ANSWER:
Question: When was the aircraft introduced that could seat 115 people?
Columns: ['Aircraft', 'Introduced', 'Retired', 'Seating', 'Notes']
Types: ['text', 'real', 'text', 'text', 'text']
Sample row: ['Airbus A319-100', 2004.0, '—', '156', 'In service']
SQL:

assistant: SELECT AVG("Introduced") FROM "Table" WHERE "Seating" = '115';