It has always happened
In the 90's it was Bolton, Sunderland and Middlesbrough who were bouncing back and forth
the 00's mostly WBA and Sunderland
What really stands out for me is League One, where as historically you may have had a lone 'bigger' team drop down in isolation, when you look at the names that are there at the same time..
Ipswich
Sunderland
Sheff Wed
Charlton
Bolton
Portsmouth (playoffs pending)
All historically decent size clubs with premier league history.
It wouldn't surprise me to see the average attendance in that league next season to be close to the Championship.
That is now becoming the definition of a nightmare league to get out of, how the likes of Lincoln and Oxford are competing towards the top, is incredible