CREATE TABLE table_name_41 (year INT, outcome VARCHAR, championship VARCHAR)

Tell me the sum of Year for outcome of runner-up for world darts championship
SELECT SUM(year) FROM table_name_41 WHERE outcome = "runner-up" AND championship = "world darts championship"
SELECT SUM("year") FROM "table_name_41" WHERE "championship" = "world darts championship" AND "outcome" = "runner-up"