When the corinthians have a position of less than 5, what is the average against?
CREATE TABLE "torneio_rio_s_o_paulo" (
  "position" real,
  "team" text,
  "points" real,
  "played" real,
  "against" real,
  "difference" text
);
SELECT AVG("against") FROM "torneio_rio_s_o_paulo" WHERE "position"<5 AND "team"='corinthians';