Historical Swiss Pass Opened/Closed Information

[DangerDoom]

Hoping the collective PH wisdom might have yet another trick up the sleeve...

Is information on when the Swiss passes were opened/closed over say the last 20 years available anywhere? Ideally would be a simple table with passes down the left, dates across the top, and a simple open/closed at each intersection. Have googled extensively but unfortunately had no luck but would imagine the Swiss might record this kind of information.

Any suggestions?

[VerySideways]

There's a great website to tell you when the passes are open or closed, and that site also has some links to various other pieces of information including historical data...

This is the site:
https://www.alpen-paesse.ch/en/

This could be the document you're looking for:
https://www.alpen-paesse.ch/en/alpenpaesse/spluege...

[Paul.B]

Very useful.