Default tax shows strange information

When I add a new sale price, if I select 21% tax, it shows strange information (21/5.2/-19%) instead of simply 21%. What does the other data mean? Is it a bug or is related with something?

Thanks a lot.

Are you running 16.0.5? that is rather old, v19.0.1 was just released.

Might it be a translation issue? And what kind of taxes did you enable in your setup?