What is the number of averages having a balls faced over 297 and more than 7 innings?
CREATE TABLE "sri_lanka" (
  "name" text,
  "innings" real,
  "runs_scored" real,
  "balls_faced" real,
  "average" real,
  "s_r" real
);
SELECT COUNT("average") FROM "sri_lanka" WHERE "balls_faced">297 AND "innings">7;