when was the episode premiere if the production code is 11.19? 
CREATE TABLE "table1_2226817_12" (
  "no_in_series" real,
  "no_in_season" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" text
);
SELECT COUNT("original_air_date") FROM "table1_2226817_12" WHERE "production_code"='11.19';