The thing about both the Chelsea and Spurs (and Arsenal to a large extent also) attendance figures, is that often the short-fall in capacity is actually due to away fans not taking up their allocation. Particularly in recent seasons when we've seen a variety of clubs with larger fan bases relegated such as Saudi Sportswashing Machine, West Ham, Sunderland, Sheffield United, Birmingham City, while clubs with also larger fan bases like Leeds, Nottingham Forest, Derby County, Sheffield Wednesday etc are still languishing in the lower-leagues.
There's been a bit of a situation developing in English football where a lot of the country's traditionally best supported clubs, particularly Leeds and Sheffield Wed are in the lower divisions, while the BPL has been filled with pretty small clubs by comparison, with clubs like Swansea, Wigan, Burnley, Stoke, Southampton, Blackpool and Bournemouth spending far more time in the top flight than you would have expected. While it shows these clubs are well run when compared to their 'bigger' rivals, what they do bring is an inability to fill away allocations consistently and thus an actual decrease in average attendance across the board.
