What was the share of votes when there were more than 56 electors and the year was more recent than 1950?
CREATE TABLE "presidential_elections" (
  "year" real,
  "electors" real,
  "votes" text,
  "share_of_votes" text,
  "candidate" text
);
SELECT "share_of_votes" FROM "presidential_elections" WHERE "electors">56 AND "year">1950;