The numbers are used to compare. You can figure out % difference between two settings for example. That’s all. Possible outcomes were in the range of 0 to 255.
If you want to read about how I came up with the numbers, I’ll put that link at the bottom of this post. Basically, they are the resulting brightness observed by a making the printer’s laser draw into a long-exposure camera. The laser is still just a dot waving around, but the pictures it draws is a complete slice of the object printed.