For Bergen and Monmouth counties the amounts appropriated for PFRS contributions in their budgets do include a buffer. I do not have access to their check registries but billing history does go back to 2017 on the state website and those amounts do approximate what is reported as charged in their budgets with the excess appropriation reserved (mostly and with 2021 still to be adjusted). Not so in Union County where I do have check registry data going back to 2005 and it shows $1,360,304 unaccounted for.
BERGEN COUNTY
MONMOUTH COUNTY