It’s for season 18/19. Fulham, Luton and Huddersfield weren’t in the Championship. I’m guessing that West Brom and Stoke aren’t included as they haven’t submitted figures for 18/19 yet, and it wouldn’t provide a reasonable comparison to provide their 17/18 figures, as they’d be from a Premier League season. Swansea, who came down the same season, are included as their 18/19 accounts have been published.