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_28 (year INTEGER, country VARCHAR, location VARCHAR)
### Question:
What is the average Year, when Country is "U.S.", and when Location is "Edmond , OK"?
### Answer:
SELECT AVG(year) FROM table_name_28 WHERE country = "u.s." AND location = "edmond , ok"