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_14 (capacity INTEGER, stadium VARCHAR, current_manager VARCHAR)
### Question:
What is the capacity for the stadium of kadrioru stadium and a current manager of sergei ratnikov?
### Answer:
SELECT AVG(capacity) FROM table_name_14 WHERE stadium = "kadrioru stadium" AND current_manager = "sergei ratnikov"