CREATE TABLE table_73979 ("Episode" FLOAT, "First broadcast Denmark  (  DR1  ) " TEXT, "Official TNS Gallup ratings" FLOAT, "First broadcast UK  (  BBC Four  ) " TEXT, "Official BARB ratings" TEXT)

When was the episode with a 999,000 BARB rating first aired in Denmark?
SELECT "First broadcast Denmark ( DR1 )" FROM table_73979 WHERE "Official BARB ratings" = '999,000'
SELECT "First broadcast Denmark ( DR1 )" FROM "table_73979" WHERE "Official BARB ratings" = '999,000'