Statrep - mem.allocated.Process and mem.allocated.Shared

I am working with at customer to collect informatoin from statrep.nsf about the Domino server performance. We have configured the statistics collector (events4) to collect information from all servers within the Domain. We have set no Statistic filters.

When I go through the statrep.nsf to get information about memory almost all servers are missing the fields mem.allocated.Process and mem.allocated.Shared. It displays for 3 servers where all are lower version than 8.5.1 FP1.

Does anyone know why these fields are missing? What can be done to get the statistics collector task to collect this information and add it to statrep?