What is the value in 1971 when 30 is the value for 1969?
CREATE TABLE "grand_tour_results_timeline" (
  "1965" text,
  "1966" text,
  "1967" text,
  "1968" text,
  "1969" text,
  "1970" text,
  "1971" text,
  "1972" text
);
SELECT "1971" FROM "grand_tour_results_timeline" WHERE "1969"='30';