Thank you milgod. I know it isn't rocket science. I was trying to save time by seeing if they had been worked out already. Historychick - the secondary DH hadn't made the document themselves. It was sent to the school. I doubt very much that sublevel thresholds would be something anyone would get their kicks from. Analysing data is a big part of management as you may one day grow up to find out. If you didn't know the answer to the original question- I wonder why you wasted time replying. After getting no kicks whatsoever from looking at numbers before school, in my break, lunchbreak and after school - teaching all day - I just have time to colour my pie charts in before bedtime. And I won't bother asking a question on here again.