What is a visit over time? That sounds cumulative, but is it just the total visitors over 28 days divided by 28?
... honestly confused about how you can have one day spikes. edges are surprising enough, if you things go up by 5x and then go right back down I think there's a bug in the code. Did the spike go away on June 2nd and get removed from the sum?
It doesn't really matter, this isn't a race and all the federated clients... federate... it's just a strange graph.