What is set 3 when set 5 is na, set 1 is 21-25, and set 2 is 25-16?
CREATE TABLE "results_pool_f" (
  "date" text,
  "score" text,
  "set_1" text,
  "set_2" text,
  "set_3" text,
  "set_4" text,
  "set_5" text,
  "total" text
);
SELECT "set_3" FROM "results_pool_f" WHERE "set_5"='na' AND "set_1"='21-25' AND "set_2"='25-16';