Crystal Reports How to calculate % of running total in crosstab

Message

     Hi everyone,

I am currently working on a report that has running totals. At the end of the report I would like to provide a summary of the running total.

For example:

Region 1
             [RTotal] (Count of Open Cases) e.g. "40"
Region 2
             [RTotal] (Count of Open Cases) e.g. "60"

Summary CrossTab would show:

Open Cases (%)

Region 1

[Percent of RTotal] (40/100) = 40%

Region 2

[Percent of RTotal]
(60/100) = 60%

please let me know if this is possible...or if there is any other way to obtain this result. 

thank you.