I don't know anything about coding, but the table looks to me like each axis outputs it's co-ordinances at a specific spot in the string, & each axis has a value that varies from 0 to 255, so I guess if everything is dead center the string would be either all 127's or all 128's... there is no actual center, as it would be 127.5....
I could be totally wrong though, but that's what it looks like to me
I'm really not trying to help, as I know nothing about this, just curious if my understanding is correct?