What 1951 has dne for 1948?
CREATE TABLE "grand_tour_results_timeline" (
  "1935" text,
  "1936" text,
  "1937" text,
  "1938" text,
  "1939" text,
  "1940" text,
  "1941" text,
  "1943" text,
  "1945" text,
  "1946" text,
  "1947" text,
  "1948" text,
  "1949" text,
  "1950" text,
  "1951" text,
  "1952" text,
  "1953" text
);
SELECT "1951" FROM "grand_tour_results_timeline" WHERE "1948"='dne';