Cumulative Frequency Table and Pivot Table

Hi
Is it possible to create a cumulative frequency table with Pivot Tables?
e.g I have a set of data summarised into 5 segments with units #

I can use the pivot table options to produce the 2nd column (% of Total in Column) or 3rd Column ( running total) but I cannot find a way to get the 4th column ( cumulative % running total ?)


data# %total run to ***%
a 40 40% 40 40%
b 20 20% 60 60%
c 30 30% 90 90%
d 5 5% 95 95%
e 5 5% 100 100%


I want to be able to use the data to produce charts without having to copy and paste data to create seperate charts.