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_62 (opened INTEGER, city VARCHAR, stadium VARCHAR)
### Question:
What is the average opened year of Mini Estadi stadium in Barcelona, Spain?
### Answer:
SELECT AVG(opened) FROM table_name_62 WHERE city = "barcelona, spain" AND stadium = "mini estadi"