Damon & Paddy D
Thanks for your interest in this problem. After some consideration I came to realise that it is impossible to visually display (in terms of area) relationships between more than two sets(circles) in a venn diagram. If you can prove me wrong in this I would be very impressed! I got round the problem using shapes to create 4 eclipsing ovals (a job in itself!) which in terms of area did not represent the extent of the relationship, but with text boxes I was able to show the relationship between sets in percentages.
From a very cold London Town, Barry