How many Tries against has a Try diff of –17 and Points for smaller than 80?
CREATE TABLE "pool_2" (
  "team" text,
  "tries_for" real,
  "tries_against" real,
  "try_diff" text,
  "points_for" real,
  "points_against" real,
  "points_diff" text
);
SELECT COUNT("tries_against") FROM "pool_2" WHERE "try_diff"='–17' AND "points_for"<80;