how many times does the episode called "coop de grace" appear 
CREATE TABLE "season_6_1997_1998" (
  "no_in_series" real,
  "no_in_season" real,
  "title" text,
  "director" text,
  "writer_s" text,
  "original_air_date" text,
  "production_code" text
);
SELECT COUNT("no_in_series") FROM "season_6_1997_1998" WHERE "title"='\"Coop de Grace\"';