What is the Nationalist share of the poll for the response in which Undecided/No Answer received 29.2%?
CREATE TABLE "opinion_polls" (
  "date_s_released" text,
  "polling_institute" text,
  "nationalist" text,
  "labour" text,
  "democratic_alternative" text,
  "undecided_no_answer" text,
  "lead" text
);
SELECT "nationalist" FROM "opinion_polls" WHERE "undecided_no_answer"='29.2%';