Pivot Table i need an average of a row

[#1]

I currently have a pivot table built in my document.

The dimensions are

Customer, Origin, Destination, PickupWeek

Expression= Sum(TripCounter) <----This is just a "1" added on to each record to save me from doing a count.

I want to get an average of the rows in my table (See Attached):

			PickupWeek
Customer	Origin	Destination	8/1/2009	8/2/2009	8/9/2009	8/16/2009	8/23/2009	8/30/2009	9/6/2009	9/13/2009	9/20/2009	9/27/2009	10 wk Average
123	ABC	XYZ	5	5	6	8	4	10	12	17	10	5	8.2
456	ABC	XYZ	5	6	8	5	4	3	10	4	5	9	5.9

Please help. I really need this to work like this so i can replace some reports i currently send out in excel.

[#2]

			PickupWeek
Customer	Origin	Destination	8/23/2009	8/30/2009	9/6/2009	9/13/2009	9/20/2009	9/27/2009	6 wk Average
123	ABC	XYZ	4	10	12	17	10	5	8.2
456	ABC	XYZ	4	3	10	4	5	9	5.9

This is a better example so you can see the end of the row, which is teh important part

[hector]

Hi, why your avg is 8.2 for Customer 123? my calculus is 58 / 6 = 9.6

if you try sum(your_dim) / count(week)?

in every week this will be equal to the sum(your_dim), but in the total will be another value

c ya