xcode version for El Capitan

I'm trying to update my XCode for El Capitan.

The App Store seems to download it (no clue where to find any progress bar on that) and it just spins for hours. Yes it's a big download but it doesn't progress overnight. So I chose to download it and I chose 11.3.1, which can't be run on El Capitan.

So does anybody know what version I'll need to download to install a "most recent runnable" XCode?

Cheers