Hi,
I have this little charting problem. I'm sure someone will have the
solution.
It's difficcult to explain so I 've posted a picture here
www.fransysco.net/frogs/frogs.gif
You may have to zoom on your browser to see it perfectly.

I have some data in a table and it's figures about frogs in a a pond and
about how many arrive in each batch per quarter and how long they survive.
The length of survival is measured in Quarters, too.

So each quarter there's a batch of new frogs that arrive - usually 2000 in a
a batch. And I measure the survival rate of each batch.
Now, if I always had 2000 in a batch this would be easy peasy, but it's not
always the case.

Once the delivery truck was struck by lightning and the half the frogs died.
That was in 2004/Q2, so I started out with a batch of 1000 frogs.

Another time, we ran out of mosquitoes in the breeding tank and lost three
quarters of the batch.
That was in 2005/Q1 so we started out with a batch of only 500.

You can see the data and the graph here in this picture.
www.fransysco.net/frogs/frogs.gif
And if you look at the numbers graph, you can see that 2004/Q2 and 2005/Q1
don't start off in the same place as the others. The fact that there were
less frogs in the batch is obvious. But that's not what I need to know. I
need to know the survival rate in percentages regardless of the numbers.

What I want to do is get the y axis expressed as a percentage of the maximum
number of frogs in the batch. That way, every batch would start off as 100%
(of itself!) and my lines would be comparable no matter how many frogs I
started out with.

Now, I can do this by putting an intermediary table in between my data table
and my graph.
On the intermediary table I calculate the percentages and base the graph on
the that table.
That would be OK if my data table had fixed diemensions but in fact it is a
Pivot Table and Pivot Tables have a tendancy to change shape. So my
intermediary table would have trouble in adapting to the Pivot Table.

That's why I need the graph to read the numbers table but display the data
as percentages.
Can it be done?

Any help appreciated and Thanks in advance.

A.K. Fletcher