CREATE TABLE table_name_14 (capacity NUMBER, stadium VARCHAR2, current_manager VARCHAR2)

What is the capacity for the stadium of kadrioru stadium and a current manager of sergei ratnikov?
SELECT AVG(capacity) FROM table_name_14 WHERE stadium = "kadrioru stadium" AND current_manager = "sergei ratnikov"
SELECT AVG("capacity") FROM "table_name_14" WHERE "current_manager" = "sergei ratnikov" AND "kadrioru stadium" = "stadium"