user: Question: When was the episode with a 999,000 BARB rating first aired in Denmark?
Columns: ['Episode', 'First broadcast Denmark ( DR1 )', 'Official TNS Gallup ratings', 'First broadcast UK ( BBC Four )', 'Official BARB ratings']
Types: ['real', 'text', 'real', 'text', 'text']
Sample row: [1.0, '23 September 2012', 1678000.0, '17 November 2012', '1,264,000']
SQL:

assistant: SELECT "First broadcast Denmark ( DR1 )" FROM "Table" WHERE "Official BARB ratings" = '999,000';