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_57 (year INTEGER, accolade VARCHAR)
### Question:
What's the average year for the accolade 100 greatest singles of all time?
### Answer:
SELECT AVG(year) FROM table_name_57 WHERE accolade = "100 greatest singles of all time"