Some teams commit less often than others. It would be nice to see how much time has passed since the last commit to source control. You could then get a good feel for how much risk was piling up.

Example:

Bonus points if you can get the health indicator to go down if the commit time gets too long. That feature would need some configuration, however, since you'd need some notion of working hours, and different projects might have vastly different timescales of how often they should commit.