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_43 (year_joined INTEGER, county VARCHAR)
### Question:
What is the average year joined of the 277 county?
### Answer:
SELECT AVG(year_joined) FROM table_name_43 WHERE county = 277