What is the total number for November, larger than 8.53 in February, 20.21 in March, and less than 7.9 in September?
CREATE TABLE "monthly_mobile_subscriber_additions" (
  "year" real,
  "january" real,
  "february" real,
  "march" real,
  "april" real,
  "june" real,
  "july" real,
  "august" real,
  "september" real,
  "october" real,
  "november" real,
  "december" real,
  "annual_additions_in_millions" real,
  "average_monthly_additions_in_millions" real
);
SELECT COUNT("november") FROM "monthly_mobile_subscriber_additions" WHERE "february">8.53 AND "march"=20.21 AND "september"<7.9;