This object selects which underlying statistic, bytes, packets, or combined bit rate, is used to rank protocols in the resulting Top-N table, determining what 'top' actually means for that report. It matters because ranking by byte volume versus bit rate can produce different top-offenders lists: a bulk transfer protocol might top a byte-ranked list while a latency-sensitive but low-volume protocol tops a bit-rate list during a short burst. Choosing bitRateSum here would surface which protocol is currently consuming the most combined in-plus-out bandwidth right now, rather than which has moved the most total data historically.