As it was mentioned in another comment, you either leave out Safari or Edge, since there is no OS where both are available. Obviously, in order to obtain a meaningful comparison, you need to run all your tests on same OS and same HW specs.
You could easily use the same hardware, and maybe run Chrome in both OS – giving you a shared reference point. It'd also make the comparison useful to people using OS X.
Edit: I just ran the JetStream benchmark on OS X (El Cap). Results:
- Safari 10.1: 306.25 ± 5.8662
- Chrome 56: 198.77 ± 10.059
- Firefox 49: 234.56 ± 19.496 (ran it a second time after update: 235.04 ± 6.0682)