Clarify how the cards numbers are computed.

[youknowriad]

Show a message or an alert or something explaining how the numbers are computed.

[oandregal]

About the card numbers: I expected this was either the last data point received or the aggregated (median?) over the time period shown in the graph (either last 200 commits or all time).

[youknowriad]

I think it's comparing 20 commits per 20 commits (or maybe 10, I need to look at the code :P)