Birt report and restart page number for a list

Hello,
I use RTC 4.0.0. on Windows and I would like to create pdf with a BIRT report.
I have a jazz data set which is read on a list in order to report on a page just one element of my list. So, when the list go to the next element, the pdf report go to the next page.
For example, my list contains 3 elements :
  - Page 1 = Element 1 of the list
  - Page 2 = End of Element 1
  - Page 3 = Element 2 of the list
  - Page 4 = Element 3 of the list
  - Page 5 = End of Element 3 of the list

I have inserted on the header of the master page, the page number with autotext. No problem, in my example, the numbering starts at 1/5 and continue on each page 2/5, 3/5 ... etc

Problem, I would like to restart the numbering when I change of list element. I don't find the option.
For example :
  - Page 1 = 1/2
  - Page 2 = 2/2
  - Page 3 = 1/1
  - Page 4 = 1/2
  - Page 5 = 2/2

Thanks for your help
Regards
Mathieu