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_4 (fleet_size INTEGER, iata VARCHAR, commenced_operations VARCHAR)
### Question:
What is the of Fleet size with a IATA of pr, and a Commenced operations smaller than 1941?
### Answer:
SELECT SUM(fleet_size) FROM table_name_4 WHERE iata = "pr" AND commenced_operations < 1941