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_21 (entrants INTEGER, winner VARCHAR)
### Question:
How many entrants did the events won by Frank Gary average?
### Answer:
SELECT AVG(entrants) FROM table_name_21 WHERE winner = "frank gary"