WHAT IS THE AVERAGE VOTE FOR DUBLIN SOUTH, AND SPOILT SMALLER THAN 3,387?
CREATE TABLE "plebiscite" (
  "constituency" text,
  "electorate" real,
  "votes" real,
  "turnout" real,
  "spoilt" real,
  "percent_yes" real
);
SELECT AVG("votes") FROM "plebiscite" WHERE "constituency"='dublin south' AND "spoilt"<'3,387';