How many runs were there when the high score was 55 and there were more than 12 innings?
CREATE TABLE "performance_against_each_opponent" (
  "matches" real,
  "innings" real,
  "not_out" real,
  "runs" real,
  "high_score" real,
  "average" real
);
SELECT SUM("runs") FROM "performance_against_each_opponent" WHERE "high_score"=55 AND "innings">12;