text: ﻿SELECT		date_time,
  		tube_diary_stop,
  		concentration,
  		station_name,
  		saturday_entry
  FROM		tube_pollution_mapping
  LEFT JOIN	passenger_numbers
  ON		tube_diary_stop = station_name
  WHERE		species = 'PM25'
  AND		environment = 'CAR'
  AND		tube_diary_stop IS NOT NULL
  AND		line <> 'Docklands Light Railway'
  AND		tube_diary_stop <> 'Hammersmith'
  UNION ALL
  SELECT		date_time,
  		tube_diary_stop,
  		concentration,
  		station_name,
  		saturday_entry
  FROM		tube_pollution_mapping
  LEFT JOIN	passenger_numbers
  ON		tube_diary_stop = station_name
  AND		line = line_if_present
  WHERE		species = 'PM25'
  AND		environment = 'CAR'
  AND		tube_diary_stop IS NOT NULL
  AND		line <> 'Docklands Light Railway'
  AND		tube_diary_stop = 'Hammersmith'
  ORDER BY	date_time