I know E4 broadcast Season 9 as that was the first season I watched. I think that was the season added due to the writers strike in America, and maybe that was affecting E4 programming too? (Wikipedia says that Season 4 was broadcast on E4 also).
I have no idea how many people watched, but I keep thinking that the UK should at least try switching to the US format to see if interest can pick up again, and since the US version is only three nights per week it isn't over-kill like the UK version might be, with it being on every night.