How many marks are there when tackles are 3?
CREATE TABLE "season_statistics" (
  "year" real,
  "team" text,
  "number" real,
  "games" real,
  "kicks" real,
  "handballs" real,
  "total_disposals" real,
  "marks" real,
  "tackles" real,
  "goals" real,
  "behinds" real,
  "goal_accuracy_pct" text,
  "brownlow_medal_votes" real
);
SELECT "marks" FROM "season_statistics" WHERE "tackles"=3;