With essays and unis, it is normally plus or minus 10%.
However, if it says no more than, I would say your word count should be between 900 and 1000 words.
I would suggest not going over that as at one point, my word limit was about 1000 words and I was about 68 words over (I took out absolutely everything I could possible but left it at that as it only made sense in that format).
If you go under, particularly 22%, I am certain they would reduce your mark for your word count alone, so would you fail, unlikely, would you be penalised, almost certainly.
Try and find other examples in published literature and use them as an example by explaining their findings, even if only to go over the 900 word mark.