What is the average tonnage of the ship named proletarij?
CREATE TABLE table_name_81 (tonnage INTEGER, name_of_ship VARCHAR)
SELECT AVG(tonnage) FROM table_name_81 WHERE name_of_ship = "proletarij"
### Context: CREATE TABLE table_name_81 (tonnage INTEGER, name_of_ship VARCHAR) ### Question: What is the average tonnage of the ship named proletarij? ### Answer: SELECT AVG(tonnage) FROM table_name_81 WHERE name_of_ship = "proletarij"