Looking at this post
it says "36% unknown". No user by the name of 'unknown' appears in the revision history (screenshot just in case some wag changes his username to 'unknown')
What madness is this? Who is this 'unknown' you speak of?
OK, I'm almost sure I cracked it.
The percentage is calculated based on number of contributions and number of editors.
As you can see in the revisions, there are 6 editors (not counting the OP):
So 2 out of 6 is 33%, not sure why 36% probably some other things are counted.
As for "unknown" likely some blank field somewhere, not really sure about that one.