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_97 (years VARCHAR, jersey_number_s_ VARCHAR, position VARCHAR)
### Question:
What is Years, when Jersey Number(s) is 21, and when Position is SG?
### Answer:
SELECT years FROM table_name_97 WHERE jersey_number_s_ = "21" AND position = "sg"