The reason for this is that AVG(AHS Selection Points) is a discrete field on the rows shelf. By removing this all the values will be on the same row. The following link should provide you with further information:
Hope this helps!
Thanks for the reply.
I understand the concept of Discrete and Continuous Pills.
What I cannot workout is how to compare the Selection in the AHS Selection Parameter Dropdown against each other Result_type_name and colour the cells accordingly.
The cells % averages by Subject and result_type_name..
Any ideas gratefully received.