When a private individual is the source and 018 is the story number what is the total footage remaining from missing episodes (mm:ss)?
CREATE TABLE "table1_1889619_5" (
  "doctor" text,
  "season" text,
  "story_no" text,
  "serial" text,
  "number_of_episodes" text,
  "total_footage_remaining_from_missing_episodes_mm_ss" text,
  "missing_episodes_with_recovered_footage" text,
  "country_territory" text,
  "source" text,
  "format" text,
  "total_footage_mm_ss" text
);
SELECT "total_footage_remaining_from_missing_episodes_mm_ss" FROM "table1_1889619_5" WHERE "story_no"='018' AND "source"='Private individual';