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_24565004_15 (period VARCHAR, position VARCHAR)
### Question:
List the number of active years for attaquant.
### Answer:
SELECT period FROM table_24565004_15 WHERE position = "Attaquant"