This read-only PerfCounter64 captures an Instantaneous Bit Rate sample for this flow point recorded in the history bin, per this object's own source description. Unlike its Max/Min-suffixed siblings, this plain IBR counter gives an administrator a single representative rate reading for the bin, useful as a quick baseline when trawling many flow points for one that looks abnormal. For example, an operator scanning a table of flow points for a specific circuit could sort on cmFlowPointHistoryIBR to spot the one bin where throughput deviated most from its neighbors.