CREATE TABLE table_name_40 (season NUMBER, score VARCHAR2, venue VARCHAR2)

Which season was there a game with the score of 1:3 played at the venue of national stadium, maldives?
SELECT SUM(season) FROM table_name_40 WHERE score = "1:3" AND venue = "national stadium, maldives"
SELECT SUM("season") FROM "table_name_40" WHERE "1:3" = "score" AND "national stadium, maldives" = "venue"