What is the average total with a Rank larger than 11, a Nation of switzerland, and a Silver smaller than 0?
CREATE TABLE "sporting_events" (
  "rank" real,
  "nation" text,
  "gold" real,
  "silver" real,
  "bronze" real,
  "total" real
);
SELECT AVG("total") FROM "sporting_events" WHERE "rank">11 AND "nation"='switzerland' AND "silver"<0;