When 1.17 is the production code how many air dates are there?
CREATE TABLE "table1_20124413_1" (
  "num" text,
  "original_title" text,
  "directed_by" text,
  "written_by" text,
  "original_airdate" text,
  "prod_code" text,
  "viewers" real
);
SELECT COUNT("original_airdate") FROM "table1_20124413_1" WHERE "prod_code"='1.17';