TPlanner nbr of headers shown


I'm testing TPlanner component for a project and want to use f.ex plMonth view with dates on top and headers/resources vertical on the left side.
Testing this I can only make TPlanner to show 4 headers/resources on the left side even though I actually have 97 in this case.

So, how do I get the TPlanner to show more than the 4 header/resource items ?

Best regards