Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_30 (introduced INTEGER, seating VARCHAR)
### Question:
When was the aircraft introduced that could seat 115 people?
### Answer:
SELECT AVG(introduced) FROM table_name_30 WHERE seating = "115"