Pivot table problem

[#1]

I have created the following pivot table where the expressions are arranged in columns

Expression           Dec            Jan             jan V.s   December             avgall months)

----------------          -----          ---------         ----------------------------          ----------------------------

Admission Q        98               90                       (  90-98)/98                  (98+90)/2

I already did the first 3 columns but last 2 no solution at all

[#2]

Do you have a sample file? It would be easier to help you.