Exactly as described, this counts 65-to-127-byte frames transmitted on this benchmark port. This bucket typically only fills during an EMIX-sequence test rather than a single fixed frame-size test, so its count relative to the other buckets is one way to sanity-check that a configured EMIX mix, rather than a fixed size, actually generated frames across this range. For example, an EMIX sequence using the small "a" (64) and "b" (128) letters would populate this bucket only lightly, since most frames land just above or below its edges rather than inside it.