I've been asked to analyse entry/exit data for an office to find out the minimum number of people present in the building for fire safety reasons. The building operates 24/7 so there should always be more than one person present.
I can say how many people have entered, and how many people have exited, but the data is anonymous so I can't say who has entered or exited.
I am using the formula below to work out how many people are in the building:
Present(n) = Present(n-1) + Enter(n) - Exit(n)
I think this can pick up trends - when people tend to enter and exit, and when it is likely there are few people around, but it cannot tell me how many people are in the building because I don't have Present(n=0), and as far as I'm aware this is not something we have.
I am sure there is a way to do this, but I have hit a dead end and would really appreciate some advice.