What episode number in the series originally aired on April 27, 1999?
CREATE TABLE "table1_228973_5" (
  "no_in_series" real,
  "no_in_season" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text
);
SELECT MAX("no_in_series") FROM "table1_228973_5" WHERE "original_air_date"='April 27, 1999';