It’s only % of salary (day fines) for more severe offenses, in this case for really speeding. Normal speeding tickets are just a set sum.
Here’s a pic showing the amounts. It has the speed limit, how much over the limit you were and how much you end up paying as a fine. Bottom one is “regardless of the limit” and “over 20 km/h”, so whenever you go over by over 20 km/h, you pay “day fines”.