Pivot Table Formula - 2 fields

[djm023]

I've created a pivot table in the following format:

'Sales $ per Unit Sold'
Mar Apr May
Customer1 $1.00 $1.50 $2.00
Customer2
Customer370
Total

There are more columns but for example purposes this should be adequate.
The dimention 'Sales $ per Unit Sold' is a formula that divides the
undisplayed columns 'Sales $' by 'Unit Sold'. What I'd like to do is create
another column with a formula calculating the month-over-month % increase in
'Sales $ per Unit Sold'. For example:


(formula???)
'Sales $ per Unit Sold' 'Mth over Mth Increase'
Mar Apr May Mar Apr
May
Customer1 $1.00 $1.50 $2.00 na 50 33%
Customer2
Customer370
Total

Is this possible???

Thanks in advance for your help.