What is the average NGC number that has a Apparent magnitude greater than 14.2?
CREATE TABLE "5901_6000" (
  "ngc_number" real,
  "object_type" text,
  "constellation" text,
  "right_ascension_j2000" text,
  "declination_j2000" text,
  "apparent_magnitude" real
);
SELECT AVG("ngc_number") FROM "5901_6000" WHERE "apparent_magnitude">14.2;