Benchmark units #576

Hey, a friend linked out your system and it certainly looks impressive; well done 🙌 😄

I noticed the benchmark table doesn't seem to display units in any of the columns
https://github.com/OpenHFT/Chronicle-Map/tree/ea/benchmark
are these time-based, or how much of the workload could be churned through? If they are time based, can units be added so it's clearer if this is sub millisecond, sub-microsecond, per minute, per second

I'm guessing millisecond as the ceiling is 2,000; but I'd like to be sure.

thank you