Docker Backend MaxConn Setting Explanation

New to traefik and this is probably a simple question, but the docs don't make it apparent. I am using traefik 1.6; when I set "traefik.backend.maxconn.amount" and there are multiple instances running in the backend, does the amount apply to each instance separately or does it apply to the backend as a whole? For example if I set it to 10 and I have 5 instances running in the backend, does that mean each instance has a max of 10 connections or that those 10 are spread out over the 5 instances? I suspect the latter, but cannot figure it out based solely on the docs.