How can I change the showed idems page 5,10,etc

Where can I change the items per page? In backend is for example the field "Default Items Per Page:" = 8
In frontend, category display, "Show: 5.10.15,20 etc. " This I want to change. Where can I change it?
Reason: In the configuration above it will be only the first 5 items displayed and not 8.

Thanks

Hi again Andreas,

I have already answered you via ticket system. Values of option 5, 10, 15, 20, etc are fixed values in default Joomla pagination and we can not change them.

Sincerely, Giang