Thanks for posting your question @fretscha
I can see that the estv.admin.ch links lead to a 404, but the CSV data is attached directly to the article. I’m attaching copies here in case your browser doesn’t allow you to download embedded streams.
Besides that, I would go through a search of the ESTV site (click Dokumente) to see if more recent data was published there or where the pages went.
Unfortunately, ESTV, the Federal Tax Administration is not yet on opendata.swiss, but clearly this could be a good opening line for a conversation about publishing some of their public data.