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_56 (tier INTEGER, postseason VARCHAR, season VARCHAR)
### Question:
What is the average Tier when the postseason shows -, and the season is 2012–13?
### Answer:
SELECT AVG(tier) FROM table_name_56 WHERE postseason = "–" AND season = "2012–13"