When did nswrfl has a score of 8-21?
CREATE TABLE "runner_ups_10_62" (
  "year" real,
  "opponent" text,
  "competition" text,
  "score" text,
  "venue" text,
  "attendance" real
);
SELECT "year" FROM "runner_ups_10_62" WHERE "competition"='nswrfl' AND "score"='8-21';